We've seen more than our share of new laptop bags that adhere to TSA guidelines for getting through airport security quickly. Almost all follow the same basic premise of a two-compartment bag that butterflies open to lie flat on the X-ray machine conveyor belt. The separate compartment that holds your laptop isn't allowed to have any pockets or any other items (wires, iPods, magazines, etc.) in it, so the TSA checkers can get a clear view of your laptop without requiring it to be pulled out of its bag and run through the machine by itself.
The latest one we've checked out is Belkin's FlyThru, and it scores highly by both working as a security checkpoint bag and also being a generally good laptop case on top of that. We liked that it could fit a standard 15-inch laptop without being too bulky, and its generally sharp looks (in fact, we've gotten a couple of e-mails from readers who have seen the Belkin bag used in laptop photos for system reviews on CNET and wanted to know what bag it was).
The shoulder strap, however, was not our favorite -- the clips that attach the strap to the bag are both on the top edge, and were too close together, which made the whole thing feel a little unbalanced.