Plus CacheSense is the first third party app to use the Geocaching Live API - which means you get all the immediate access to cache information you get with the Groundspeak apps and much much more.
I use a Blackberry Bold with CacheSense and am having a very difficult time finding a 'real' GPS that is just as good. Just make sure you get yourself an Otterbox Defender case - it keeps the BB nice and safe.