Have you seen the new Keyword tool in Adwords that lets you type in a domain name and see what keywords are being used to reach that domain? It's very good for spying on your competitors without forking out for keyword research tools.
Sorry guys but I think I may be missing the point on this one. What makes this tool so useful? I does not seem to offer me any of my competitors keywords. As a matter of fact the Help section makes this seem very similar to the Keyword Tool in Adwords. It even offered me very similar keyword groups (mostly about web design or hosting). Is it providing more interesting results for people with different types of keywords? If I am missing something here please let me know. Sometimes it can be hardest to see the thing that is right in front of you.
It just looks like another keyword suggestion tool, by analysing the data on the website you enter. So, it's quite useful for quickly indexing the keywords on a competitor's site, (and praps plagiarising them?!) but it certainly doesn't show what your competitors are bidding on as far as I can see.
I think you make a good point winsoar. The terminology is a little misleading. Do you have a preferred tool non-Google tool for analyzing competitors?