Personally, I use keywords for searches. This allows me to kill the search bar and just go to the url bar and type "g empeg" to search Google for empeg, or "d loquacious" to look up a word in a dictionary. I haven't looked at the Google toolbar for Firefox, but the only thing I can think that I'd like to add that the IE toolbar has is the automatic highlighting, but that's only minor.

I've described the keyword thing on the BBS before. I don't think it should be too hard to search for.