There is also a IE and Firefox toolbar that allows topic search, keyword search, and even unlikely features like pop-up blocker, search highlight, and site ranking displays.

So now we have Qwika for search on search on wikis, Twing for search on internet forums, Truveo and Blinkx for video and audio search, and Pipl for people search, besides the omnipresent Google. Good for researchers.

Also check out Top Online Research Resources for PR and marketing Professionals