I have done it, and it is fun. And HARD! You would think, that if you have the exact coordinates for something, that you could walk right up to it, but that just isn't so. GPS units are only accurate to within a few meters, and that makes all the difference. And some folks go to great lengths to hide the geocache, and if it is a little one--whew!
I have a friend who is a dedicated geocacher--he takes his GPS with him on vacations and business trips, and always manages to find a few.
I just haven't been the same
since that house fell on my sister.