Here is a nice and quick way to integrate twitter with your wordpress blog .
1. Download twitter-tools from http://downloads.wordpress.org/plugin/twitter-tools.1.1b1.zip
2. Extract it into wp-content/plugins/ folder and activate it from dashboard , After enabling it just activate features of twitter-tools from Options menu
( I have activated tweeting on my each blog post, That`s great. And all my daily tweets get digested and made into a new blog post each day, Awesome)
Let me know what changes you all are looking into it !
Update: Inegrating Movable type with twitter http://www.chopstixmedia.com/mt-twitter/