What about the Dahon Curve SL? It is light, 16-inch wheels, and 8-speed hub (so less fuss with damaged derailleur from airport abuse).

The prof who owned this bike put it into a 29-inch Oyster hardcase with room to spare for clothes, just by removing the two wheels. Took him 4 minutes to pack or unpack.

You can see the photo below in my attachment.

http://speedmatrix.dyndns.org:8328/~...php?topic=33.0

It may be the right bike for you if you travel so much.