Bruce Nicholson pointed the other day to an add on for IE call IE 7 PRO (You can get it from http://www.ie7pro.com) which has some great features. His main one to show me was th spell check feature which allows you to spell what you type in web pages. You can see the difference it made to my potjie article Before and After. This is really nice but not my favorite featre.
My favorite is the crash recovery, should IE or Windows crash (which my Vista install does when I sleep it in a hurry) the next time you open IE it prompts you to restore the last session. If you say yes it opens all the tabs to the locations you were at. AMAZING :)