What are the differences between iPhone 2G or iPhone 3G?

i would say that the battery time on the 2G is better. The network connection is more stable on the 2g. on the 3g mobile-internet is faster, sounds are louder, GPS function is a little bit more precise. I would buy a 3G phone now if i was you, but if you can wait... theres a new iphone coming in july. But the old 2g model is still a great phone