Yahoo Inc., the most-used Internet site, has shut down all its user-created Internet chat rooms amid concerns that adults were using the sites to try to have sex with minors.

Google takes its name from the mathematical term "googol," which stands for a 1 followed by 100 zeros, a number said to be greater than the sum of all the particles in the universe. Obviously few of us, save perhaps a handful of farsighted astronomers, have need for a word that conveys so much. You can't say the same for Google. If it continues to double profits every year for the next hundred, accountants a century from now might need to represent the company's gross revenue in googols.

Some of the world's biggest advertisers, including Microsoft and Anheuser-Busch, are increasingly turning to electronic word-of-mouth advertising campaigns as they seek inexpensive, provocative and entertaining ways to reach new customers. Known commonly as viral advertising, the marketing strategy often can hide who's behind it and usually involves an online component to spur consumers to spread the message themselves with minimal noticeable involvement from the company.

Digital devices keep young people connected -- to each other. E-mail is too slow but 10 hours a day on a cellphone isn't too much.

Microsoft plans to announce on Friday that it is expanding its support for the Web publishing standard Really Simple Syndication. Most typically, RSS is used by news publishers and bloggers to notify subscribers when new information has been posted. It is also used by podcasters to alert listeners to new available audio.

E-mails to MSN Hotmail are still being received by its members, but some are being referred to junk e-mail boxes after Microsoft said all Hotmail e-mail must be compliant with Microsoft's Sender ID e-mail verification program starting earlier this week.

EBay Inc. at its annual user conference this week, will be under pressure to spell out its plans to counter looming competition from Web search giant Google Inc. The Web marketplace -- dubbed "FeeBay" by some sellers frustrated with increasing eBay fees -- is looking for ways to rebuff rising challenges from companies like Google while balancing profit margin protection and sellers' desire to keep their eBay costs as low as possible.

Crispin Porter & Bogusky and DDB Brasil each won the Cyber Lions Grand Prix at this year's Cannes International Advertising Film festival. The Miami-based Crispin earned the honor for its "Come Clean" Web site, for environmentally friendly household products brand Method; Sao Paulo's DDB Brasil won for its "Reality Advertising" site for Henkel's Super Bonder Instant Glue.

Viral advertising is spreading as a popular, efficient marketing tool, as consumers increasingly pick and choose what ads they watch and when. Viral is today's electronic equivalent of old-fashioned word of mouth. It's a marketing strategy that involves creating an online message that's novel or entertaining enough to prompt consumers to pass it on to others ? spreading the message across the Web like a virus at no cost to the advertiser.

Grokker, a visual search tool that clusters related search results together in conceptually related categories, is now available in an online version, free of charge. The I Grok search tool from Grokker uses the Yahoo web database as its index, and clusters results into "maps" with topics represented as circles. Within each topic circle, which is labeled with a descriptive name, individual web page results are represented as squares. For most queries you'll see up to nine major topics, many of which have subtopics represented as smaller circles within them.