Seos
 

anyone got any experience with spyfu.com?
or hittail.com?

i'm hearing good things from people about both sites.

I used another one of these spy services and the results were ok, but nowhere near complete. A lot of the data is outdated too (several months old) so make sure the one you pick has fresh data.
WG

I use hittail.com It's not really a spy type of service. It just lets you see the full referrer URL. It's nice for finding some nice long tail terms on your site.

From the little I've messed with Spyfu.com it's info is quite poor.