There are a lot of ways that the various search criteria can be combined and I'm sure they all would be useful to some degree. The one that I think would be the MOST useful though, is being able to narrow a keyword search by state. Whenever I've done a keyword search, I almost always feel that it returns too much information. I don't care about caches in any other state most of the time. I would suggest limiting a keyword search to your home state automatically, but I definately can see needing to seach other states sometimes, but very seldom do you want to search the entire world IMHO.