Searching Twitter is becoming increasingly popular (you can tell by the amount of spam seen in the trending topics). So, it comes as no surprise that applications are being built and expanded to leverage Twitter search.
TweetScan was one of the first applications to incorporate Twitter search and now they've expanded to include historical Tweets. You can now search a database of 220,660,667 messages from Twitter back to November 2007 (as well as 1,627,559 from microblogging network identi.ca). It's not free, though. It will cost you $20 a year. Hey, they gotta pay for the database somehow, right?
Next up is a new kid on the scene. Launching this week is CrowdEye. Their modus operandi is to examine how popular topics have developed over time. The results include a visual graph showing the number of Tweets over time, popular links on a given topic, and, of course, actual Tweets. Check out this result for "iphone" -
What do you think of these Twitter search apps? Let us know in the comments.