I bought my first Mac, a MBA, on eBay about 3 weeks ago. I started a thread asking advice before I purchased (thanks for the help!). Anyway, I loved the form factor, but it was a acting a little quirky which Macs aren't supposed to do. I went to register it with Apple, but they didn't recognize the serial number. I immediately assumed it was stolen. The guy included the original box, but the power cord he sent was for a regular MB. Plus, he didn't send recovery discs. So I took it to an Apple store, and they spent some time trying to find information on this machine. It turned out I got a preproduction model from last August (the revB Air shipped in Oct). No wonder it was flakey. I got a great deal ($1150), but I wasn't keeping it since it wasn't eligible for Apple Care and was a preproduction model. I'm getting a refund from the seller, but I was wondering where he got ahold of a preproduction unit. I usually have tremendous luck with eBay, but after this issue I just went to the Apple store yesterday and bought a MBA new with the SSD. Boy is it faster than the regular HDD version I had. I am loving it!