Jon C has this huge stuff sack type thing. Its got a shoulder strap and one handle, fastens a bit like an old fasioned army kit bag. Stops stuff gettin snagged on conveyor belts and the like. You can use cable ties to secure the top, same as JD suggested.
Only problem with the cable ties, is that you cant carry anything to cut them with in your hand luggage, so work out a solution before you fly!!
Si(C)