The iPhone5 definitely works, but is a tight fit. I also found that the adapter without the cable doesn't allow for any "give," and has disconnected itself a couple of times. The adapter with the cable works better, but then you have about a foot of extra cable to tuck away somewhere. I've decided to leave the CVO 8GB ipod in for general day-to-day use and commuting, because hooking up and disconnecting the iPhone every time I stop and leave the bike is somewhat of a PITA. However, for an extended ride, the iPhone makes more sense, because it has 16GB of storage. I should probably just go to Best Buy and get a 16GB iPod Nano for $100 or so.
Side note on the included iPod Nano... I took it out of the bike after the first ride & put it in my shirt pocket. I then bent over & it fell out of my pocket, hit the garage floor, and shattered the glass

. I put a screen protector on it to hold all of the pieces together & it still works, but this tiny thing is easy to lose, easy to drop, and apparently pretty fragile. A word to the wise - buy a protective sleeve/case for it.