By now everyone whose discovered the Internet knows about finding background on people at two of the most popular social networking sites — Facebook and My Space. But you may not have ventured into the microblogging world of Twitter, where people are just as unguarded, albeit in smaller doses — messaging in less than 140 characters. Use the advanced search function to find words and phrases in the body of a message or find someone by user name. If a participant is writing under their real name try finding their postings by putting their first and last name together, or just the first initial with the last name. Search by full name in a profile here.The use of pseudonyms makes it harder to find your subject, but check the user names she has at other sites.

Follow topical threads and users by RSS or receive instant updates to your mobile phone. [UPDATE 2014: Bad link removed.Mydigimedia] devotes a post to Twitter applications that extend your Twitter features, and other Twitter related services — including a few that give you other ways to search. Blogger Phil Bradley reminded me of the alternative search engine, Icerocket, which now has Web, Twitter and Image search in addition to its long-standing blog search. Enter your search terms, select “Big Buzz” to see search results grouped by blogs, Twitter, News Feeds and Images. Track new appearances of your search terms through RSS.