More stable folding

Does anyone know of any way of adapting a Friday which has a rack fitted, so when it's folded it stands upright when resting on the rack? I was thinking of fitting some kind of roller wheels like the Brompton or an upside down kick stand or something.

I know the new commuter Friday borrows similar ideas to the Brompton, but I don't really want to buy a new bike!

I commute daily on a train with my Crusoe so it would realy help.

Thanks.