alanw and others: thanks for the great help!
I am still a bit worried, however, since I've read before that Korean wCDMA/UMTS operates on the 1900 frequency up and 2100 down, although now I can't find a reference so I hope I'm wrong.
So I'd like to know: has anyone actually *used* a 3G handset with only the UMTS2100 successfully in Korea? And if so, did it work in Japan too?