Atwitteration
Atwitteration has many popular Twitter features hard coded in so there is no need to worry about plugins! Features include automatically generated Tiny URLs for every post, your latest Tweet is automatically displayed in the header, Tweet This link after every post, Follow Me On Twitter link in sidebar, automatic detection of a visitor from Twitter and displays a short message inviting them to retweet, and includes 125×125 advertising ready block in the sidebar. Simple instructions in the Readme file.
License: Free to use must keep footer intact AS IS