Those worried about the longevity of their tweets have another reason to relax. The Social Archive, which also stores status messages for many StatusNet-powered sites, is entering the Twitter search game. It joins Topsy, Tweet Scan and Twitter's own search engine, which received a recent upgrade.
Did you think the search engine wars were over, and Google won? New kid on the block Blekko, currently in closed private beta, urges you to reconsider. Once out, it's bound to become the favorite of search refiners, with the results likely made available as an API.