Disable Admin Bar disables the admin bar that now appears on the public side of WordPress 3.1 (beta) blogs.
Twitter Blackbird Pie allows you to add awesome looking embedded HTML representations of actual tweets in your blog posts just by adding simple shortcodes.
WP Event Ticketing makes it easy to sell tickets to an event directly from your WordPress website.
wpStoreCart is a free, open source, and full featured e-commerce platform built atop of WordPress.
Easy FancyBox enables the FancyBox 1.3.3 jQuery extension on all image, SWF, YouTube and Vimeo links.
jQuery Lightbox For Native Galleries makes the native WordPress galleries use a lightbox script called ColorBox to display the fullsize images.
WP SlimStat is a simple but powerful web analytics plugin for WordPress.