Automattic Stats will collect visitor and feed stats from your blog and display it in the WordPress.com Global Dashboard.
Easy AuctionAds is a free plugin for wordpress that allows you to easily integrate AuctionAds into posts using different keywords.
AWSOM Drop Down Archive is a WordPress plugin designed to put a posts drop down archive link box above your posts area on your index and individual posts page.
WordPress Excerpt Editor provides a convenient place for creating and editing all of your excerpts. It can “auto create” excerpts using the first 40-55-70-100 words from the content, optionally retaining some of the HTML tags and add custom excerpts for pages.
WP Post to Twitter will notify Twitter everytime you make a new post.
Blogtimes Map is a wordpress plugin that shows when the blogger posted in the last period of time, and allows a visitor to click on the blogtimes Image Map, and be taken to the corresponding posts.