I'll try to explain the usefulness of GPS devices. It stands for Global Positioning Systems. The military has been using them for years. Now consumers can buy them for flying a small plane, finding a good fishing spot, for boating as well as for car purposes. I purchased a GPS unit for rental car purposes and haven't looked back since. I find them to be more up to date than internet maps. You download the information needed and can use waypoints to get back to your hotel and such. I'll be using mine when I'm going to Sagamore Hill (Teddy Roosevelt) in June and then a quick trip to the Hamptons.

Hope this helps, Nelly MS