Discover what hashtags mean, and add your own definitions in seconds.
Discover what hashtags really mean.
Tagdef iPhone app - look up hashtags from your iPhone.
DuckDuckGo - The search engine with privacy protection.
Truthy-a research project that helps you understand how communication spreads on Twitter.
Solplay-A simple, modern way to search twitter.
Twittelator - the most powerful iPhone twitter-client.
Tagdef in Firefox (uses Greasemonkey)
Tagwalk - web-application for twitter-analysis.
Tagscroller - Open source jQuery plugin for showing hashtag definitions.