Cheap, durable labels for equipment?

So I lost my Canon Rebel on the airplane over the weekend (ouch) and despite reaching Newark's lost & found, it doesn't look like I'm going to recover it. I probably won't be able to get a new camera until after the New Year, but at least I have my compact.

I figured it's time that I labeled my equipment-iPod, cameras, Zoom H4, pedals--so I give folks a better chance to be Good Samaritans. Does anyone have any suggestions for labeling that will work on a variety of different pieces of equipment? I was thinking of those tough-to-remove foil labels? Or maybe there is a certain pen that leaves a durable mark? Something that will work on a variety of surfaces.