The only one I can think of is the google toolbar thing... It has a little bar that shows the "importance" of a website based on searches or something. I know lots of people on FR use it. then again you have to download their software...no free lunch.
The only rankings I've seen are top 100 or so, and FR isn't high enough to make that list (but neither is hannity I'm sure)
Most of the top 100 were company websites if I remember right...online shoppers I guess.
I don't use the google thing either.