prepaid cards
not sure if these pre-paid cards are actually credit cards or debit cards. But be wary of losing the protection of the "credit" card when paying abroad. It has saved me a couple of times when stuff went astray.
I keep a US bank account to simply US purchases. I get frustrated at not being able to pay for gas on my UK credit card without walking backward and forward to the kiosk and often finding that they would even then not process it manually.