Avid and successful twitter users use hashtags to categorize their tweets. Putting a hashmark or pound sign (#) and then a keyword which relates to your tweet, will allow you and others to search for that later. This is good when multiple users are tweeting about the same subject.
Let’s say for instance that you wanted all of your tweets and re-tweets about The Big Tweet (TBT) to be indexed for you and others in the future. Anytime you posted something about The Big Tweet you would want to include “#TBT” in your tweet. Others following The Big Tweet will do the same, creating an easy way to find tweets relating to The Big Tweet by including the same hashtag.
#followfriday is a very popular hashtag. It’s used to recommend new tweeters for your followers to begin following themselves, on you guessed it, friday.

Hashtags can also be used to track real-time events and create groupings. Experiment with hashtags for yourself and see what you can find.
You are also able to track hashtags with Hashtag.org. This allows you to search for certain hashtags or keywords and will show you real time tracking of tweets using yoru specified hashtag. Get started with Hashtag.org by simply following @hashtag.
March 27th, 2009