I recently acquired a Scottevest Tropiformer Jacket and I’m really looking forward to trying it out. It has pockets for everything up to and including a pocket for an iPad. It’s waterproof and it easily, really easily, transforms from a vest to a jacket (ok, more of a windbreaker), and back. I have a hunch that if you were clever you could pack for a week with just what you could fit into the pockets. I’m not going to try that on my upcoming trip, but may significantly help to keep hand luggage to a minimum.
I’ll report back after I’ve used it for awhile.