Userscripts.org

Checks if the blogs you're following also follow you

Display several informations about the twitter profile your looking at to help you decide wether or not s/he's worth following

Too many posts in your dashboard but don't know who to unfollow? This script helps you find who is posting the most to more effectively trim your following list.

From a users profile page there isn't a simple indication as to whether their following you or not. Here's where this hack comes in.

Calculates what type of twitter user someone is (by displaying a colored bar at the top of a twitter user page classifying the user based on Evan Prodromou's scale ranging from "twitter caster" to "twitter spammer").