I subscribe to VZnav and find it quite useful. I also have the keychain puck and find it equally beneficial. I am a Geologist and my Dad is an Engineer/Land Surveyor. The puck works fantastic in the woods while using bbtracker to record my path. I just hang the puck on my belt loop and go.
VZnav has actually shown me a 'backdoor' way into the Atlanta airport that I never considered. That itself was worth a year's subscription if you have ever driven I-285 in rush hour. Or should I have said parked on I-285 in rush hour!?
Oh, our Verizon store doesn't serve hummingbirds.