Create Reviews via Twitter 

Who thought 140 character won't make reviews?

Micro Reviews

Post reviews on Twitter

Notches

Submit reviews. A partner of Microreview

Louder Tweets

Have your reviews of certain products posted

change how you read tweets

Twitter Digest

Read tweets digest-style

Tweet2tweet

Read the conversations between two people on twitter.

Twalala

Choose the tweets you wants to read. Mute people or mute topics that you don't want to read

Track your followers as well as your own following behavior

Tweet Wheel

Find out which of your friends know each other

Twitter Karma

Find out who is following and unfollowing you. Have a mass follow and unfollow tool.

Twitter Snooze

If you have noisy twitter friends, you can snooze them for a certain time so you won't receive their tweets.

My Tweeple

Evaluate your followers through the number of dings (recommendations) they have from other Twitter users

Less Friends

Find out who unfollowed you using this tool

Qwitter

Receive the names of the people who unfollowed you via email.

Does Follow

Tells you if a certain follower is following a person or not

Twitterless

Receive a direct message when someone unfollows you

Twitter100

Find out the latest 100 posts of your followers

Twitterator

Follow a list of people all at once

Twitter Who

Invite lots of people in one go

Twitterlex

See your last 30 tweets along with your friends. Use on Mac.

What's Up?

Find out what people are up to

Tools that can integrate Twitter to your site or blog

Add Tweets

Make Twitter Update Widgets for site or blog using javascript

Twitterfeed

Post your blog to Twitter through your RSS feed

Feed Tweeter

integrate Twitter with Plurk, your blog and delicious

Twitter Counter

Display your follower count on your site or blog.

Twit This

Add this option so people can easily tweet information from your site or blog

Twitter Tools

A wordpress plugin that lets you integrate Twitter with your blog. You can send your updates to your blog as well as create tweets directly from your blog

Twitter for Wordpress

displays latest tweets on your blog

Loudtwitter

Ships your tweets to your blog

Twitter Sharts

'Shart' your twitter status anywhere within your wordpress blog posts or pages

Twitt Twoo

plugin that will allow you to update your Twitter status right from your blog's sidebar.

Twitter Updater

automatically sends a Twitter status update to your Twitter account when you create, publish, or edit your WordPress post

Twitter Wordpress Sidebar Widget

a wordpress widget where you can send your tweets to your blog

WordTwit

a plugin that utilizes the Twitter API to automatically push a post to your Twitter account when it is first published.

Comment Twitter SMS Notification

plug in to be notified by SMS when a user post a new comment on your blog.

Stammy's RSS To Twitter

Not too many people have access to a Ruby-enabled server so the author decided to make a simple PHP script to get the job done.

PingTwitter

automatically update your Twitter Account when you publish a new blog post

Post to different social networking sites at once

Ping.fm

Update twitter along with other sites like Multiply, Pownce, Plurk, tumblr and others.

Hello.txt

Same as ping.fm but with added services

Moodblast

A client which you can download. It does pretty much the same as ping.fm