I'm a pretty tech savvy person, and I loooove the new iPhone 3G. I got it in 16gb black, although I'm kicking myself because I kind of wish I got the white now. The applications available from iTunes are awesome!!!
You can also "jailbreak" your iPhone so you can download even more free applications and change the theme of your iPhone.
It's so much more than just a phone. It's pretty much my lifeline now. I synced it to my MacBook so that I can easily transfer my address book and calendar. And, like I mentioned, the applications make it such a handy piece of equipment. They have apps for everything under the sun, like common French phrases, movie times, dictionaries, games, drink recipes (cocktails), currency converters, etc etc. My favorite program is Shazam. Basically, if you hear a song on the radio and want to know what it is, just open Shazam and tag the song. It will record a clip of the song and tell you immediately what song it is and who sings it.
I am a huge, huge advocate of the iPhone. I do admit, the touch screen keyboard did take some getting used to. My accuracy is still a little off, but give a day or two, you'll get much better at using it. It's kind of like wearing contacts. The first week is the hardest, then after that it's a breeze.