Welcome to What the Hashtag?!, the user-editable encyclopedia for hashtags found on Twitter
What's a hashtag?
Hashtags are a community-driven convention for adding additional context and metadata to your tweets. They're like tags on Flickr, only added inline to your posts. Hashtags can be created by anyone simply by prefixing a word with a hash symbol: #myhashtag. Hashtags were developed as a means to create groupings of related content on Twitter.
This is an interesting way to access and index content, and adds an extra level of usefulness to Twitter.