Directories

• GeoFollow - Local Twitter Search - Geo (location based) twitter directory. (Add youself on twitter by sending @geofollow YOUR CITY, YOUR STATE YOUR ZIP #tag1 #tag2 #tag3. EG: @geofollow Walnut Creek, CA 94596 #directory #geek #people. Largest location based Twitter Directory on the net.
• TweetFind.com Online Directory of Twitter Businesses & Users - Free to Submit
• twitboy - all men on twitter
• twitgirl - all women on twitter
• Twitter-Athletes - A directory of verified professional athletes on Twitter. (NFL, NBA, MLB, NHL, Soccer, Golf, Tennis, MMA, etc)
• Politwitter - Canadian political twitter, list of Canadian MP's and MLA's tweeting.
• Followformation - Quickly follow dozens of categorized Twitter users.
• LocaFollow - A Tool For Searching and Following Other Twitterers - A Twitter search engine that enables you to locate and follow Twitter users by searching in their Bio and Location fields.
• Twibes Twitter Groups - Twitter affinity groups. Find people with similar interests.
• Tweeple411 ~ World's first Tweeple driven Directory. Find people with similar interests to follow or add your Twitter or FriendFeed page. Power to the Tweeple!
• Twitter Directory 2000 - Twitter users that have a minimum of 2,000 followers and have updated status within the last 30 days. Also offers follow and be followed status.
• Twitwho - Human-edited directory of Twitter users organized by categories.
• Zellr - Directory for twitter users. Members can link their twitter profiles with facebook, twitpic, rss, digg and other accounts in a single profile.
• Twapps.com - A twitter gallery that show cases all twitter applications. Growing daily.
• Twitter News - Latest news about twitter at one place
• Twi5 - A one stop shop for finding cool twitter applications.
• Twtapps - We develop simple, fun and useful twitter apps. Our apps don't require username/password!
• App list - A monster list of all web based twitter applications: http://i-stuff.blogspot.com/search/label/Twitter
• TwtBiz -  is business directory for Twitter. You can find businesses, entrepreneurs, investors! See the company's team Twitter feed. (by @twtapps)
• ComedyTweet The daily lives of the funniest comedians on twitter -- all in one place! (follow us at @comedytweet)
• PornStar Tweet! The daily lives of the hottest Porn Stars on twitter -- all in one place! (follow us @pornstartweet)
• ALTGirlTweet! The daily lives of the hottest ALT Models on twitter -- all in one place!  (follow us at @altgirltweet)
• WebGirlTweet! The daily lives of the hottest Web Girls and Cam Girls on twitter -- all in one place! (follow us at @webgirltweet)
• GlamTweet! The daily lives of the hottest Glamour Models on twitter -- all in one place! (follow us at @glamtweet)
• BBWGirlTweet! The daily lives of the hottest BBW Girls on twitter -- all in one place! (follow us at @bbwgirltweet)
• GayStarTweet! The daily lives of the hottest Gay Porn Stars on twitter -- all in one place! (follow us at @gaystartweet)
• PornExec Tweet! The daily lives of the hottest Porn Executives on twitter -- all in one place! (follow us @pornexectweet)
• The Social Archive Topical Directory of Tweets with Downloadable Archives.
• TwitterStates Twitter Directory for United States. (follow @TwitStates)
• Hash Dump  Registration of Twitter hashtags.