Instead of having to pack a cable to charge your camera, if you've got a Mac laptop or an iPod PSU, you can use the 'duckhead' attachment (the bit that actually plugs into the wall) and use it with your charger.
Most camera chargers use a "figure-of-8" lead - it looks like a...well... figure of 8. Apple's power supplies for iPods and Mac laptops use a *slight* variation on tihs, but the connection is actually the same.
Most chargers are the same, they are a small box with the mains connection right on the edge with no gap or obstruction. Simply attach the duckhead to the camera charger, and plug it into the wall. I have tested it with various Olympus chargers and UK/EU/US attachments, which all work.
The great thing is that the duckhead, when connected to the charger, seems to be pretty solid - it's actually quite stiff so it's not going to fall off in the middle of the night.
YMMV, but on the whole, a great way to save having to pack another cable, and it's also less clutter.