Noticed recently I've been using Twitter for well over a year now (February 5th 2007 to be exact), and some might say I've become addicted. I'm closing in on the 2500 twitter post mark, have about 465 followers and follow 241 of those myself.
Now to be honest, things have come to a point where things are beginning to get a bit too crowded on my friends timeline.
When Aral twittered about looking for a way to unfollow twitter users that don't follow him back I started looking for an easy way to do that. Was looking for all sorts of crazy mashups that would help manage friends but in the end found a very simple way to get it done.
If you're logged in and go to your friends overview (http://twitter.com/friends) you'll likely notice that there are certain users that you can direct message and certain that you can't.
When you can't message that user it simply means that he's not following you back. Going through that list you can easily remove those users.
Doing this I went down from 300+ people I follow to my current total and it does help. There are a handful of people I still follow even though they don't follow me back, if you're one of those people its safe to assume I'm a big fan.
Think its important to note that you can still message with people you're not following by using the @user syntax, if someone writes a twitter post that has @peterelst in there I see it show up in my replies tab (sort of, twitter can be a bit dodgy when a message has multiple @ references).
If you want me to follow you on twitter, a good way is to message something to me using @peterelst and chances are that I'll add you.
Also worth mentioning is the increase in Twitter spam, what I tend to do is check the ratio between followers and following -- if the amount of people they follow is over double that of people that follow them its generally a spam bot and block those.
Have been trying to write an AIR app to go through the friends list and gives the option to automatically unfollow those that don't follow you as well as detect possible spam Twitter users.
Unfortunately have been running into the 70 requests per hour limitation very quickly so might need to be a little bit creative in how to get around that problem.