New member living in the Denver area. I'm a private pilot and I purchased the iPad2 3G so I could use it for navigation. I set it up with WingX Pro and a Dual bluetooth GPS receiver. The package works great and has far exceeded my expectations. I now use the iPad for far more than just the navigation and it has become a must have wherever I go.
I recently flew a Cessna from Denver to Lakeland, FL and the navigation system was excellent. It accommodated route changes due to weather conditions and provided me with all the details I needed about airports in the vicinity of where I wanted to stop for refueling. WingX pro is an excellent app and the Dual GPS works great. It has replaced the clumsy charts and books that I used to need to fumble with in the cockpit in order to get airport details, runways, frequencies, etc. I got a mount for it that sticks to the window and I can easily follow the map as well as look up information as I need it. The GPS is accurate to within 12' vertically and horizontally which is really fantastic.
The problem is that I've become somewhat of an App junkie. I'm controlling it to some degree, but when I have some time to kill I spend it looking for apps and buying more than I really need. Cheap, fun entertainment.