This time UDG have a rucksack or shoulder bag hybrid that is tough enough to protect your laptop and will fit in the hand-luggage compartment on airlines.
The bag is available in a range of colour combinations including the gaudy urban camouflage and the subtler green/gold (pictured here).
There's a combination lock to slot your zips in if needed plus tons of places to carry your kit.
The only gripe is that the rucksack straps cannot be removed or stored away easily if using the bag with the detachable shoulder-strap, but all-in-all it's another piece of musician-specific luggage worth looking at.