great phone!
(had all the iphones before that as well).
the speaker is louder, i no longer have to go to full volume to hear everything (which i did on the 2g).
the voice control function is also pretty amazing, and it's only been wrong once (i've had the phone since early summer).
a lot of space, video quality is alright as well, although it's not wise to use at night or in a club, because you wont be able to see anything.
but the great selection of games and apps these days is also just amazing (saying this incase this would be your first iphone).
the 3g internet is pretty fast, everything seems to load swiftly except for youtube, which is fine once the video has begun loading, but it takes quite a while for most videos to start.
it's an amazing phone, and being on twitter, facebook, and myspace this phone has pretty much helped me in incredible ways to keep up my friendships and stay in touch during my busy work days.
one con is the headphones are supposedly the same but they added a volume control next to the mic, which is great, but it seems the plug headphones are a little bigger then before, because my left ear hurts a little after using them for over 3 hours. which it didn't on the old ones, but maybe it's just the ones i have.
i also think it's pretty cool that i can actually listen to music while i'm on the phone with my iphone, all you have to do is hit the play button during calls, (i've got a great instrumental folder for this).
the only other cons i can come up with are:
-the fact that unless you jailbreak it all decent games are gonna cost you.
-that you need itunes for just about every interaction (and even though you have everything on your iphone, you pretty much need everything to also be on your computer for you to be able to keep it on your iphone after a sync.