Social analytics firm Topsy today announced the launch of its new search engine for tweets. The company claims to have indexed every one of the 425 billion tweets sent since Twitter launched in 2006, so it's simple to instantly trace the origins of #FollowFridays, or check out the public's reaction to Obama's election. Once you type in a query, you can adjust your results by date, time, content type (photos or videos), and language.

In the absence of an official solution from Twitter, Topsy's free search engine will be vital for journalists, researchers, social media gurus, and even Twitter itself. The company used Topsy to help gather the most buzzed-about Oscar nominees. So why doesn't Twitter have its own search engine? That's not entirely clear, though the company has demonstrated its desire to make your personal tweet history a bit more transparent.