Consumers might not get so many fraudulent e-mails purporting to be from companies such as PayPal, eBay and Washington Mutual Bank if they could be sure the sender is who the sender claims to be.

That can be accomplished through digital signatures, a form of e-mail encryption that verifies the senders identity. Typically they appear as scrambled code at the end of a message. But in order for such a system to work, it must be widespread.

Tech giants Yahoo and Cisco are trying to make that happen with a technology called DomainKeys Identified Mail, or DKIM. DKIM goes before an Internet standards body next week. The stamp of approval is important if it's to be adopted by e-mail senders and Internet service providers.

Guest: Eric Allman, chief technology officer of e-mail security provider Sendmail.

Elsewhere:

Cisco criticized for enabling China net censors (Wired)

Hacker hippies gather in Netherlands (AP via USAT)

Microsoft wins worker poaching case vs. Google (CNET News.com)

New research finds that U.K. residents who illegally share copyrighted music online spend four and a half times as much money on legal music downloads compared to those who don't share songs.

The report from U.K. research firm The Leading Question says that rather than taking legal action against downloaders, the music industry needs to entice them to use legal alternatives.

The recording industry maintains that music sales are down overall, and they blame that on piracy.

Paul Brindley, director of The Leading Question, says on average illegal downloaders spend about five and half pounds per month on iTunes, Napster and other sanctioned sites.

Elsewhere:

Digital cinema on horizon (USAT)

A revolution on the radio (NY Times)

The birth of Google (Wired)

Yahoo announced this week it is buying the small software company that makes the Konfabulator program.

Konfabulator is used to make desktop applications, called "widgets", that display information, from local weather to news headlines to traffic Webcams.

Konfabulator gives Yahoo a new way to reach Internet users.

Guest: Houston Chronicle technology columnist Dwight Silverman

Flawed backup software is emerging as the latest target for hackers looking for corporate secrets and sensitive personal data. A survey by the nonprofit computer security research firm SANS Institute identified holes in backup software made by Computer Associates and Veritas Software.

Elsewhere:

Microsoft wipes Apple off the map (AP via USAT)

Radio program turns to blog to cull ideas (NY Times)

"Fat man walking" gains Web following (CNET News.com)

Hidden sex scenes that led to a new adults-only rating for the top-selling Grand Theft Auto: San Andreas video game could signal the start of a crackdown on graphic games.

The rating change followed pressure from politicians and media watch groups. Wal-Mart, Target, Best Buy and Circuit City said they would pull all copies of Grand Theft Auto from their store shelves nationwide.

After initially denying it, the maker of the game admitted that it includes graphic sex scenes that can be unlocked with an Internet download developed by game "modders."

The game was released in October with an "M" rating, for players 17 and older.

David Walsh with the Minneapolis-based National Institute on Media and the Family says the industry-run ratings board is broken, and needs to be replaced. Walsh says the Entertainment Software Ratings Board mishandled the Grand Theft Auto controversy.

The ESRB declined an interview request, and chose not to provide Future Tense with a written statement. The industry association for video games, the Entertainment Software Association, did not return our phone calls.

Your computer could be sending spam at this very moment.

Spammers have made zombies out of computers worldwide. They commandeer machines by infecting them with viruses, and use the enslaved computers to send shady offers for pornorgraphy, prescription drugs and mortgage refinancing.

Guests: Markus Heyder, Federal Trade Commission; Gregg Mastoras, Sophos

Internet-based phone services such as Vonage and AT&T CallVantage are touted as cheaper, feature-rich alternatives to regular old phone service.

But they are less reliable, and suffer from audio quality problems, according to an extensive study by Keynote Systems.

Many people spend hundreds of dollars every year on software. But there's a free alternative to almost every program -- from word processing to photo editing to Web browsing.

Guest: Mary Leete, author of the new book, Free Software for Dummies

Online classified site Craigslist is THE place to go for job and apartment listings, personals and other classified ads in its home city, San Francisco. It's very popular in New York City, too and is growing rapidly in other cities as it continues its expansion.

According to Internet research firm Hitwise, Miami's Craigslist grew 363 percent over the last year. Dallas' Craigslist grew 322 percent. The growth is bad news for newspapers, which are suffering from falling circulation and profits.

Guest: Bill Tancer, research vice president at Hitwise

Elsewhere:

U.N. at odds over Internet's future (BBC)

Study: Internet phone service inferior (AP via USAT)

Marrying Maps to Data for a New Web Service (NY Times)

Apple's iTunes causes explosive growth in podcasting (NY Times)

iTunes mints podcasting stars (Wired.com)

Carlos Owens has spent two years and $25,000 building a giant robot in the back yard of his Anchorage, Alaska home. It's called a "mech" -- short for "mechanical." Mechs are robots controlled by human pilots.

Owens, who works as a steelworker, says he's taken his prototype as far as he can, and needs to sell it to fund continued research and development. The price tag on eBay: 40 large.

Podcasting is only about a year old, but already there are cries that big media is co-opting the grassroots technology.

Podcasts are audio programs downloaded from the Internet to portable digital music players. Most are produced by amateurs, but many broadcasters, from National Public Radio to ESPN, are using the technology to find new customers.

Many people are getting their first taste of podcasting from the new version of Apple's iTunes software. But some podcasters complain that Apple is highlighting big media podcasts, while burying the little guy.

Blogger and podcaster Chris Doelle of Houston says amateurs are the real podcasters, and he's urging listeners to resist big media podcasts.

Dwight Silverman says Doelle's got it wrong.

Does Linux makes sense for average computer users?

Linux is an open source computer operating system. Unlike Windows or the Mac OS, its underlying source code is available to the public. Anyone can freely use, modify and distribute Linux. It's generally less prone to crashing and security problems.

Linux is used mostly by sophisticated home users and in the business world. But David Brickner says Linux is for you, too.

Brickner is author of Test Driving Linux: From Windows to Linux in 60 Seconds. His book includes a CD that allows readers to run Linux and several Linux-based programs without installing them on their computer hard drives.

Linux links:

Wikipedia on Linux

http://www.knopper.net/knoppix/index-en.html (Linux "Live CD")

Mandriva (Linux "distro")

Xandros (Linux "distro")

Minutes after last week's terrorist attacks in London, eyewitnesses uploaded digital images to online photo-sharing sites.

Members of one such service, Flickr, posted hundreds of photos, including one now-famous photo of Londoners evacuating a train in a dark subway tunnel.

Guest: Flickr co-founder Caterina Fake

Elsewhere:

107 cameras to monitor space shuttle for problems (Phys.org)

Microsoft denies anti-spyware tool favors adware maker (CNET News.com)

Group pushes for hybrid cars with plug-ins (Wired.com)

Internet users worried about spyware and adware are shunning specific Web sites, avoiding file-sharing networks, even switching browsers.

Many have also stopped opening e-mail attachments without first making sure they are safe, the Pew Internet and American Life Project said in a study issued Wednesday.

"People are scaling back on some Internet activities," said Susannah Fox, the study's main author. "People are feeling less adventurous, less free to do whatever they want to do online."

Elsewhere:

London mobile networks jammed (BBC)

Blogs respond to London blasts (BBC)

Wikipedia's entry for London bombings (Wikipedia)

The leader of the robot pack (CNET News.com)

Intel, Morgan Freeman to offer movies over Internet (AP via USAT)

Florida man arrested for Wi-fi theft (St. Petersburg Times)

The Internet age has created challenges and opportunities for those trying to communicate with oppressed parts of the world. One such organization is Radio Free Asia, a nonprofit funded by the U.S. Congress.

Guest: Managing editor for the Web, Catherine Antoine, who heads up RFA's online operations.

One feature at RFA.org that has gotten attention in recent weeks is Wild Pigeon, a story banned by China after it was published in the original Uyghur. It's author was jailed, but RFA has maintained a translation on its web site.

(Jeff Horwich guest-hosts.)

Elsewhere:

Blog bares demons of sex offender apprehended in Idaho (Wired News)

Napster, Dell is college music sharing alliance (Reuters)

Hackers crack Sony PSP; Sony issues fix (GamesIndustry.biz)

Live 8 streaming breaks records at AOL (Associated Press)

While the internet has made the world a smaller place, it can also amplify our obsession with news in our backyard. The same political, technology and celebrity items get bounced around among bloggers and other media, sometimes without much room for new perspectives and issues.

Global Voices Online is trying to counter that trend. The web site is a digest of blogs from around the globe -- especially developing countries. It was founded by former CNN correspondent Rebecca MacKinnon and a researcher and blogger named Ethan Zuckerman, with the Berkman Center for Internet and Society at Harvard Law School. Zuckerman (our guest on the show) says they started Global Voices out of concern for how little news the media carries from developing parts of the world. (Jeff Horwich guest-hosts.)

Elsewhere:

Want to build a wooden iPod? (from Bit-Tech.net)

China signs up to anti-spam act (Silicon.com)

Wireless technology breakthrough offers cheap long distance broadband (PC Pro)

Microsoft's personnel puzzle (CNet's News.com)

The just-released version of Apple's iTunes includes something beyond the usual line-up of downloadable music. Apple is distributing some 3,000 "podcasts" -- online radio shows, many of them homemade, that you can subscribe to and take along on a portable audio player.

Though podcasting is not exactly new, it has yet to attract much more than a niche audience. Apple's move could change that. (Jeff Horwich guest-hosts.)

Guest: Peter Rojas, editor of the technology web site Engadget. Engadget itself has a podcast that is now listed on iTunes.

Future Tense, we're glad to see, was not left out of the fun. Go to the podcasting section of iTunes, search for us -- and there you go. If you don't have or don't want iTunes, you can still subscribe to the podcast the original way right here.

Check out blogger Rex Hammock, who has also devoted a great deal of thought to the pros and cons of the launch of podcasting on iTunes.

Elsewhere:

An interview with Apple's Steve Jobs on podcasting (ABC News)

China treats addicted video game players (Associated Press)

Handheld device-maker "Go" revives antitrust suit against Microsoft (CNet's News.com)

Bullseye: Deep Impact slams into comet (Space.com)

Silicon beats carbon in chess battle (The Register)

This week, Google gave the public the chance to download -- for free -- a new program with the humble name Google Earth. Google has mapped the entire planet, using satellite imagery it obtained when it bought a company called Keyhole. (Jeff Horwich guest-hosts.)

Guest: Brad Hill, who reviewed Google Earth for The Unofficial Google Weblog -- and now can't take his hands off it.

My thoughts: This thing sucks you in. It's remarkable -- and remarkably easy to use, though you'll need a fast computer with a good graphics card. The program's not perfect -- a search for Taj Mahal took me to Las Vegas. One very interesting, out-of-the-way spot is Dili, East Timor. It looks like the country was still in revolt at the time the satellite image was taken, and you can see fires burning throughout the capital city.

At the Google Earth site, be sure to check out the pages of sight-seeing spots and the potential business applications.

Stephen DesRoches at Newrecruit.org also has done some writing on Google Earth. He's mostly pleased with the product, but he has some concerns. Among them, he tells me he'd like to be able to take it with him and use it offline -- say on a laptop, in a car, for navigation.

Elsewhere:

Google, Yahoo offer a peek at mapping code (CNet's News.com)

Shuttle Set for July 13 Launch, NASA Says (Washington Post)

Brand X Decision Stokes VOIP Worries (Light Reading)