American Express now has a service called “Serve”, which works kind of like PayPal, where you have a web account that you can easily link a bank acount/debit card/credit card to and transfer money to the account as you wish, free of charge. They send you a free serve card, which can be used to draw funds from this account, wherever AMEX is accepted.
I think the checkbook/moneychanger idea might be the best though since you don’t have to worry about where cards are accepted.