Gonex made a backpack you can fold up and pack in a backpack. Or, I guess more realistically, a suitcase you're taking to Asia that your lady can then unfold and fill with a thousand dollars worth of tchotchkes for the living room. Gonex's packable backpack is made of water- and tear-resistant nylon and folds to fit into a sandwich-sized 6" x 6" pouch. Use it as a daypack during camping trips or treks to the beach/around the city while on vacation.
Gonex also suggests overenthusiastic packers avoid extra fees by taking one of their folding bags to the airport to whip out and use as a carry-on if checked suitcases tip the airline's scale.
The 20-liter pack has 3 zippered compartments, breathable mesh shoulder straps, and a bottle holder on both sides. It weighs 6.5 ounces. Available in 8 different colors.