Hand luggage for long flights/journeys

Agreed that a couple of day's worth of spare clothes are a must if you're flying with a layover somewhere. An eye mask is pretty crucial for me if I plan to sleep at all (well, I usually use a scarf or slouchy hat for this purpose to avoid carrying extra things) and I guess ear plugs too for those inclined, but I'm not personally a fan and normally just play my ipod at a lowish volume (i.e. quiet enough that cymbal crashes or such won't wake me up).

There was this pretty good thread not too long ago with loads of travel tips that's worth a look if you haven't seen it already, some of that will be relevant.