Welcome to WebmasterWorld Guest from 188.8.131.52
The site is back today, with a new logo that looks nothing like Google's colorful logo so I assume the site received a C&D and changed their look.
Anyway, you can have fun with it and it may or may not be somewhat useful for determining keyword associations.
I'm not going to post the link again, never got a sticky as to why the link was pulled but hindsight makes me think it was the resemblance to Google. A search will turn up the site, which by the way, I have no affiliation with, just found a link to it on another forum and checked my moniker and thought, "hey, cool."