The new service will allow Twitter users to connect to their Twitter accounts through third-party websites such as eBay - similar to the way Facebook Connect allows Facebook users to sign into other websites using their Facebook accounts.
The announcement was made at the South by Southwest conference in Texas. The @anywhere platform will allow Twitter users to interact with Twitter even when they are not on the Twitter website - they'll be able to, say, follow their favourite columnist from The New York Times, or Tweet about a particularly appealing bargain on eBay, without ever having to leave the third-party's site.
When users browse a site that implements @anywhere, people and brands with Twitter accounts will appear as hyperlinks. Hovering over the hyperlink will reveal a box with that person or brand's Twitter info and most recent Tweet (clicking on the hyperlink will take you directly to their Twitter profile).
A Twitter blog post notes that the primary purpose of @anywhere is that "website owners and operators will be able to offer visitors more value with less heavy lifting".
It does seem a lot like Facebook Connect, although Twitter will have to work hard to displace Facebook's grasp on the web - after all, one of the biggest draws of Facebook Connect is that users can log into sites using their Facebook accounts instead of going through a lengthy registration process. By contrast, Twitter's @anywhere looks like it will only make one's Twitter account more interactive - and not replace any login screens. Of course, more details are yet to come, so it may be more (or less) like Facebook Connect than it sounds.
To stay up-to-date (Twitter-style) on the new service, follow @anywhere on Twitter.