I just posted these on my blog and thought some of you might appreciate them too:
1 - Valebrity
This site will let you check whether that celeb profile you've found is real or not.
2 - JustTweetIt
A good side for finding Twitterers with similar interests to you.
3 - Twestival
A growing group of Twitter users raising money for charity.
4 - TwitPic
My favourite app for sharing your photos with Twitter users.
5 - Twittervision
Let's you see where in the world people are twittering from.
6 - NearbyTweets
A cool app that shows Twitter users in your area.
7 - Twitterjobsearch
Yes - there's a way to find work on Twitter too.
8 - Tweetwasters
See how much time you're wasting on Twitter.
9 - BiggerTwitter
Let's you post messages longer than the usual 140 characters.
10 - Twitbacks
Some nice free backgrounds for your Twitter profile.
11 - Tweetstats
Check out the statistics on your Twitter use.
12 - Tweetlater
A really useful little application that let's you schedule your posts for later, and some other cool functions too.
13 - TweetWhatYouEat
Helps you keep a food diary if you're dieting.
14 - SnapTweet
A site for sharing Flickr photos on Twitter.
15 - WeFollow
Directory of Twitter users, tagged by subject areas.
16 - Twellow
Like a Yellow Pages for Twitter users and services.
17 - Twitaddict
Add your name to the list of Twitter addicts.
18 - Twitterholic
An up-to-date list of the top 100 Twitter users with the most followers.
19 - TwitThis
A site to help website or blog visitors share a link to it via Twitter.
20 - FriendOrFollow
List of users who you're following but that aren't following you back.
21 - MeTweet
A personal assistant to help you find new people to follow.
22 - TweetBeep
Alerts you whenever you're being tweeted about.
I hope you find those fun and useful.