Graphic search engines

I was sad when I found out that grokker went out of business =( (http://blog.ecorrado.us/2009/09/01/grokker-gone/). It was an innovative way to present search results.

However, I did a search online and found that there are other graphical search engines available now. Here is a list of the ones I found that I like. They present the results in a graphical way. Some of them group the results by topic, date, etc.

Eyeplorer: http://eyeplorer.com/show/
Search Cube: http://search-cube.com/
Quintura: http://www.quintura.com/

I think these sites are good for education purposes.