A GPS can be handy if you don't know whether you're coming or going. It can be used to find your location anywhere on earth to within a matter of feet. It gives you your elevation, distance traveled, and can even show you the way back to you're field vehicle if you get hopelessly lost.

A Brunton pocket transit is a must for any field expedition. Think of it as a compass on steroids. Your Brunton will eventually become your best friend, with it many uses. You can use it to find strike and dip, shoot a bearing... it even tells you which way is north!

The almightly geology hammer... perfect for beating on outcrops or the heads of irritating classmates. No geologist would be caught dead without one. I personally recommend the Estwing brand. Geology hammers and picks come in several shapes and sizes.

A hand lens is another useful little item. They're great for getting up close and personal with your samples. Looking at a rock at 10x magnification can be very informative, after all.