Let the hive mind of Engadget get that for you.
"I'm looking for a pair of quality headphones that aren't seemingly made of glass. I'm an avid BMXer which causes me to frequently bash on any type of technology that joins me for my daily riding. I've been through the higher quality headsets in the Skullcandy line as these are supposed to be built for "abuse," which is laughable. I cant wear earbuds or canal buds, as my large ears seem to have a repelling property upon anything that sits in them. Wired or Bluetooth doesn't really matter, but I need something that can hold up to taking a few hits every now and again. I'm trying to keep 'em under $150. Thanks!"
lower price
higher capacity storage and faster disk speed
longer battery life (3 hours average isn't good enough an hour more would be more respectable, 5 hours... don't know where that came from)
Wireless iPhone, iPod Touch syncing
I'd also add a piece of software to put on your main mac that would allow you to sync up files over airport/3g (itunes libraries, photo albums, documents...) between your main mac and the macbook air so the content on them is current.