Here's another Wikipedia related item that I meant to post about the other day.
Powerset is a site that does semantic analysis of Wikipedia and Freebase search results, trying to highlight information that more closely matches your query, and to show the essence of the content.
For example, click the following link to see the top result for "What is a merkin?". I particularly like this image from that page, which was taken at Burning Man :-).
Presumably, they will start handling content from other search engines over time.