I just got my iphone 3g as well and found my first two caches yesterday. I think they were both ranked easy, made easier by having google maps hi-res imagery (caches in downtown Atlanta, Georgia Tech campus). Battery power in general seems to be an issue with the phone, but then again it's my first smartphone type device.
I used only the geocaching.com website and the google maps program on the phone, not any additional geocache app. Geode looks really nice, and I'm considering trying Geopher. I'm really new to all this (obviously)...
