twtrfrnd.com is a web app that allows users to find common followings between any two Twitter users.

Features:

• simple web UI
• find common followings between Twitter users and which people that one follows that follow the other
• displays results in avatar grid

The Good:

If you are curious about someone who is following you, you can enter your username and theirs, and twtrfrnd.com will perform a search which will show (a) how many people you follow, (b) how many people they follow and who follow them, (c) the common group that both follow and (d) an indicators group of people you follow that follow the second entry. All of this will be displayed in an avatar grid. You can hover over an avatar to get the Twitter bio information for that user.

The Not-so-Good:

twtrfrnd.com puts up a lovely display, but we wonder mightily about its utility. Rather, we wonder what to do with the information it produces. It will certainly indicate any commonalities between you and the selected user. If you are looking for others to follow, it might be more useful to have a display for those that the other follows but you do not.

Tweetwave.com rates it: ♦♦