After weeks of restricted beta testing, full real-time search functionality on Twitter is now available to all visitors to its website.
The home page at http://twitter.com/ now features a sidebar search box, and a list of ten Trending Topics - the most popular words in recent Tweets.
According to the official Twitter blog, "Every public update sent to Twitter from anywhere in the world 24/7 can be instantly indexed and made discoverable. With this newly launched feature, Twitter has become something unexpectedly important—a discovery engine for finding out what is happening right now."
The results seem to bear out the claims. All the search result Tweets have time-stamps - and for a currently popular phrase like "#bbcqt" (BBC Question Time), the latest Tweets are less than ten seconds old.
There's a link to 'Save This Search', which adds a dedicated link on your home page sidebar, where you expand or collapse the various search lists.
Twitter Search also has its own distinctly Google-esque home page, for public visitors, at http://search.twitter.com/. This allows for advanced searches with Boolean operations or hashtags, and to restrict results to certain Twitterers, locations (with a radius), dates and even attitudes.
If you've had enough bad news you can search only positive :) results, while misanthropes can celebrate their schadenfreude with only unhappy Tweets. (Although neither of these were working at the time of this post).