Topsy: Now Searching Tweets Back To May 2008, Danny Sullivan, Search Engine Land (Aug 24)
“Looking for old tweets? Look to Topsy. The service has just expanded to have what it claims to be the largest searchable collection of past tweets, over 5 billion of them, stretching back to at least May 2008. That makes it more comprehensive than Google’s Twitter search or even Twitter’s own Twitter Search.”
Danny Sullivan says that Topsy and Google are the only two search engines that will dig into the archives. Topsy has advanced search and syntax.