Watch your competitor's domain

If you own a web site, you probably use some tracking system and know your keywords and positions in Search Engines. But what about your competitors?
About an year ago there was some service allowing to see top web site keywords, but it was rather limited.

And now we have an interesting service - SeoDigger.com.

Parsed approx 44,000,000 keywords with depth of 20 first Google results!

That's what they say. They used top 50kk keywords with the most traffic to parse the output from Google and saved in their database.

I guess it's useful for a good check - you get listing with keyword, position in Google and traffic estimates in Overture and Wordtracker.
Very interesting tool!