I know you're probably going to get lots of pro air mattress votes, so in the interest of sticking up for the little guy

we love our sleeping pads!
We tried a friend's air mattress and every time one of us moved at night the other person was getting bounced around all over the place. And there's a good chance a better quality air mattress wouldn't do that...so attention all air mattress lovers; I'm not doggin' your mattress!
We bought 2 Therma-rest XL (32"Wx80"L) inflatable sleeping pads (they expand to 2" thick) and we love 'em! We push them next to each other and share blankets just like we would with an air mattress. Once they are deflated and rolled they probably take up about the same amount of cubic space as a deflated, folded mattress in your gear. The advantage, as you might imagine, is they are very light weight.
One tip if you decide to buy sleeping pads. The manufacturer recommends keeping the pads inflated between camping trips. If they are kept rolled up the foam inside the pad will want to stay "squished" even when you inflate it. I guess foam, like people, resists change.
Whichever way you go, I wish you a good night,
sleep tight
and don't let the bed bugs bite!