Yahoo has released a beta version of My Web 2.0, a so-called "social search" engine that accepts contributions from its users. My Web layers editorial content on top of standard search results to make it easier for users to find what it is they are looking for.

Perhaps inspired by the success of Wikipedia, social search content is fleshed out by members of "trusted communities" that tag Web pages with their own comments and insights to share their knowledge of the Web with other community members.

The tagging concept was taken from Yahoo's recently acquired Flickr photo sharing service.

Communities are formed when Yahoo members reach out to other members by inviting contacts to join their personal network by e-mail, or by importing their existing social relationships from other Yahoo Web properties such as Yahoo! 360 blogs and Yahoo! Messenger.

"Over time, we envision communities using My Web to build their own search engines to capture and make accessible the knowledge of their community – search engines populated with the collective experience of a group of medical researchers, a community of PHP experts, a bird watching club, or members of a structural engineering consulting firm," Yahoo's David Ku of Technical Yahoo! Search, and Eckart Walther, VP Product Management of Search, wrote in the Yahoo Search blog.

Yahoo's "MyRank" search technology takes social search content and combines it with traditional algorithmic search results to improve relevance. In its simplest connotation, social search culminates in more personalized results.

Personalized search is also supported by Yahoo's My Search History, which allows My Web users to save, search and share Web pages.

Users decide what content is shared with whom by designating tags as either global, community or private. Tags are structured by users to provide complementary information to the original Web pages such as maps and locations.

Google launched its own Personalized Search product on Tuesday that ferrets through the accumulated archival content of Google Search History to improve search results over time.

For more information on Yahoo's social search efforts, subscribe to the My Web blog.