More than you think, probably.

I'm on a Blackberry by choice although that's probably due to the fact that the iPhone a) is on Rogers and b) wasn't available a few months ago when I needed it for work.

Not unhappy with the choice I made (I have an iPod Touch that I use regularly as my media device) but I am very keen to see what functionality v2.0 of the iPhone/Touch software will really enable me to have with the Apple devices.