InlineTweet.js allows you to easily create tweetable links out of any text on a webpage. Just wrap the tweetable text in a container with
data-inline-tweet and it's ready.
tweetParser is a minimal jQuery plugin that automatically parses @usernames, #hashtags and URLs within your text and turns them into Twitter links by using regular expressions.
Tweed is a jQuery plugin for displaying a simple feed of recent tweets.
HubInfo is a jQuery plugin to show information about your GitHub repo. It weights at only at around 2KB and has a tweet option included.