Twitter is a great streaming feed for news and information, but what you get depends on who you follow.
While Twitter does provide suggestions based on whether they are "promoted" or who you already follow (i.e. follow Joe because they are "followed by" Julia), it doesn't tell you a lot of information about them except their Twitter handle, short profile, location, basic stats, etc.
A new service called Twtrland helps you decide who to follow by providing lot's more information and displaying it in an organized fashion--simply plug in the Twitter handle you are interested in knowing more about and you get the following:
1) Basic Info--Picture, profile, stats on follow/follower/tweets
2) Top Followers--Let's you know who else (from the who's who) is following this person.
3) Advanced Stats--Provides measures on how often he/she gets retweeted, tweets per day, retweets, etc.
4) Graph of Content Type--Displays in pie chart format the type of content the person puts out there: plain tweets, links, pictures, retweets, replies and more.
5) Samples of Content by Category--Examples of this persons tweets are provided by category such as: famous words, plains tweets, pictures, links, retweets, and mentions.
I like the concept and execution of Twtrland in organizing and displaying tweeters information. However, I cannot really see people routinely taking the time to put in each Twitter handle to get this information. Making a decision a who to follow is not generally a research before you follow event. The cost-benefit equation doesn't really make sense, since it doesn't cost you anything to follow someone and if you don't like their tweets, you can always change your mind later and unfollow them if you want.
Overall, I see Twtrland more as a profiling tool (for research or interest) by getting a handy snapshot of what people are doing/saying online in the world of micro-blogging, rather than a decision support system for whether I should add someone to my follow list or not.
(Source Photo: Twtrland Profile of Sylvester Stallone, Rocky!)