My absolute favorite feature in MSIE 7.0 is the custom search providers. If you can search via the URL's query string, you can use it. One of my most used custom searches is BugMeNot, the compulsory registration bypass web site. It's easy to set up BugMeNot so you can access it as easily as Google:
Go to the search dropdown and select "Find More Providers"
On the web page that comes up, type http://www.bugmenot.com/view/TEST as the URL and BugMeNot for the name.
Click install. Now you can search BugMeNot straight from IE7.