search

Utwitbook is a place to find top twitter people who share your interests, location, url and even design colors. On the home page, it also list the most popular words in the bio, location and url field.

GeoChirp helps you search for people Twittering for specific things in a specific area.

Twitter search engine that allows you to put a Twitter search box on your site

This is an app that lets Twitter users find businesses on Twitter.

It makes very heavy use of twitter search to provide track-like functionality to end users.