Smart Mailer
When I got my Rev A, I had only a few hours before taking it on a flight. I bought a 9.5"x13.5" Scotch Smart Mailer at the local department store (and cut the closing flap off) as a "temporary" protective cover. I figured I'd case out some cases once I'd returned from my trip. The bubble-wrap, moisture resistant envelope worked so well that I never got around to dealing with a "real" case. I figured the Mailer would last a month or two, at which point I'd invest another $1.50 in a replacement. My time estimate was way off--I'm still using the original Mailer! 🙂
I do still get some strange looks when I pull my Air out of the yellow envelope (people have forgotten those original Air ads, I suppose) which to me is an added bonus. [I used the money I saved on an Air case to get my wife a high-quality case for her MBP.]