is an add-on for the Internet Explorer 7 browser that includes a lot of tools to extend IE features and security. The feature set included with this add-on is rich -- offering Tabbed Browsing Management, Spell Check, Inline Search, Super Drag & Drop, Crash Recovery, Proxy Switcher, Mouse Gesture, Tab History Browser, Web Accelerator, User Agent Switcher, Webpage Capturer, AD Blocker, Flash Block, a Greasemonkey-like User Scripts platform, User Plug-ins and more.
IE7 Pro is free and the developers update it regularly. The IE7 Pro blog has several great video tutorials on using the add-on's features; be warned, though - the videos are set to automatically play - they all play at the same time as you load the blog's main page. (Via Ed Bott's Windows Expertise)