Best Answer - Chosen by Voters
It is possible to use your Blackberry for GeoCaching, but why not buy a unit that is built for GeoCaching?
A couple of months ago I made the best investment of my life and bought a "DeLORME PN-40" and have used that to find my last 200 caches and LOVE IT!!. It's comparable to the "Garmin 60CSx" (which is the GeoCachers prefered handheld GPS).....but WAY better!! It's has everything the 60CSx has and more. It's WAAS enabled which makes it 5 times more accurate than anything else that's not WAAS enabled. The built in compass is awesome, and it has a built in GeoCaching function where you can select a cache and have it direct you to it on a map.....just follow the direction of the arrow. That screen also tells you how many feet away you are from the cache. Buy it....you wont regret it AT ALL!