Staff researcher David François Huynh has created an interesting tool for browsing semantic database Freebase, called Freebase Parallax. Written up by ZDNet's Oliver Marks, the video Huynh recorded demonstrating Parallax (below) will knock your socks off.
Excellent review of the Freebase project that includes a video of the Parralax Browser in action. Incredible stuff! Great video
Google is essentially a media company - as Tom Foremski succinctly points out here - logging your actions for Ad Word generation like a supermarket rewards card program while leveraging brute force search of the indexed web as you search for your keywords and phrases.
Wikipedia is essentially a single destination site, which means lots of laborious single issue searching.
The semantic web is a vision of information that is understandable by computers, so that they can perform more of the tedious work involved in finding, sharing and combining information on the web.