While neither Wink nor StumbleUpon have made huge inroads into the googlopoly on search, the latest announcement from Wikia (the people broadly kinda, sorta behind Wikipedia) could be very interesting.
Essentially, Wikia is looking to create an open source user-driven social search offering (there's some kind of vicious acronym in there somewhere). They have recently acquired distributed web crawler Grub which uses users' PC idle time to crawl the web. And, of course, Wikia knows a thing or two about harnessing user-driven content. Which could all lead to something pretty interesting.
BTW even as things stand right now, if you want a different spin than the results provided by the Yahoogles of the world, try searching in del.icio.us to see what others have already discovered.