Yeah man, this is something that excites me too. I had to bend over backwards and do a little dance to just be able to play ringtones on my verizon razr...
I had to record a voice memo, save it to a memory card that I had to buy separately for the phone, connect it through a CARD READER that I also had to buy separately. (a USB cable would not connect the phone to the computer - though it has a USB port... I'd plug it in and it'd just sit there.)
Then I had to change the file name of my ringtone to some retarded file name called for example 902183233.something (it had an even weirder extension that made the .mp3 about triple in size..), then save it to the memory card through the card reader. I then popped it back into the phone and it tricked it into thinking it was playing a voice memo. :\... so I have a huge long list of files titled "293842348923" - and others with similar numeric property that were essentially my ringtone files.
Hopefully with the iPhone i'll be able to plug and play and then just PICK a song I want to be my ringtone! But that's the least of my worries and excitements over the iPhone - there are so many more features that excite me as well as the aesthetic of the phone. Sorry for the long post. LOL
Nothing about this phone is particularly unique so I'm content to not say that any feature excites me a great deal.
The part that excites me the least, however, is a "full web browser" that doesn't have java or flash. That to me would not be a "full web browser" especially since my 6800 has flash 7 and java without issues.