If you have ever wished for a tool that can provide useful info about a Twitter user, check out TwitGraph. It is a nice little app that gives a comprehensive analysis of any Twitter user including their recent activity. Just enter any Twitter user name and click submit.
TwitGraph starts by showing the number of tweets the user has made in last 1 week, broken down by days. The second section shows the list of users you have mentioned in last few days, followed by the app used for your tweets such as TweetDeck or Tweetmeme. TwitGraph also analyzes the words you have mentioned most in your tweets including hashtags and the links you have posted. Each section also contains a nice colored graph showing your activity in an easy to read manner.
It is an excellent tool to judge if a user is worth following or if somebody is just there for sending spams. It also gives you a nice breakdown of apps a user tweets from, something which can tell you a lot about a user. You can click on any app, username or link shown in the analysis to go to the actual web page.
Note: It would not work for users who have made their profile private and lock their tweets.