They do a couple of smaller ones which should be pretty rigid

http://www.timbuk2.com/products/companionbags.html

But they large ones are quite floppy and anything in the main compartment has zero protection from crushing. Stuff in the front inner and outer pockets is unlikely to get bumped around a lot.

Personally I try and avoid anything small with a carry handle because of the serious risk of being given a nickname after this chap: