Search Engine Bookmarklets  - http://www.searchengineshowdown.com/bmlets/ 
Librarian and Search Engine expert Greg Notess has a great page on what a bookmarklet is and a list of the best to use for searching. If you do a lot of searching on the web don't miss this. His site, Search Engine Showdown is a must read for anyone who uses Google and other search engines to find information. He has an RSS feed for those who'd like notification when he has news to report.