Just a word of warning to all. My C3 shipped with a UK plug mains/USB charger. This turned out to be faulty and causes my C3 to flash all its buttons on and off and cycle through random tracks. Having opened the charger, it is a nasty, cheap thing that if I had known how poor quality it was, wouldn't have been near my C3 in the first place. I am now using my Kindle mains/USB charger and it is fine. As long as you check the rating on your charger to make sure it meets an output of 5v and a minimum of 500mA, any charger should be fine to use with it.
After a thorough examination of it, there is not a CE marking or anything else, to indicate the UK charger shipped with my C3 has been through any sort of testing or certification, so my advice to you all would be to avoid using it.
Do you guys/gals that received the C3 in America get a US adaptor with it ? Is it poor quality too ?
EDIT: Seems a bizarre thing to do, ship a cheap and nasty charger when the C3 is such nice quality. Very much a false economy, and affects how people see the quality of the overall package.