Similar to Yagoohoogle, DoubleTrust gives you search results from Yahoo and Google.  It is quite a bit smarter though.  It gives you the intersection of the two engines, as well as those "outside the join", or orphaned results. 

The results are displayed in a very clean and compacted list. 

This appears to be the sole work of grad student Ashish Gupta at Northwest University.  There is a blog on the topic as well.

Interesting site.  One of my favorite things is the sweet picture of the double-neck flying V guitar on the about page.

Try it out at: http://www.doubletrust.net/