Twitter WordPress Plugins

Twitter Updater
The Twitter Updater automatically sends a Twitter status update to your Twitter account when you create, publish, or edit your WordPress post. You can specify the text for the updates, and also have the option to turn the auto update on/off for the different post actions in the admin panel.
TwitThis
TwitThis is an easy way for people to send Twitter messages about your blog post or website.
Twit It Up!
Twit it up is a simple AJAX-powered WordPress plug-in that basically does the same thing as Twit this: allows readers to tweet one of your posts directly from your blog by clicking a simple link.
Twitt-Twoo
Twit-Twoo is a very useful for bloggers because it allows you to tweet friends directly from your WordPress dashboard. Particularly great if you spend a lot of time on your WordPress dashboard!
Tweetbacks
Automatically import tweets about your posts and lets you display them either as comments or separately.
Twitter Tools
Twitter Tools, created by Alex King, is one of the most popular Twitter plug-ins for WordPress. It completely integrates Twitter in your WordPress blog.
Twitter Avatars In Comments WordPress Plugin
This plug-in integrates Twitter avatars in the comment template of your WordPress blog.