There are a number of banks listed on the wiki that offer ATM/debit cards with 0-1% forex vigs and no other fees. Commerceonline.com, FirstIB.com, BofI.com and umbrellabank.com are a few examples. Most local credit unions are also options.

I still think it's better to use a credit card overses if for no other reason than it's good to have a credit line in case of an emergency (but also because it's easier to dispute fraudulent charges). Also, the smaller banks that offer 0-1% forex vigs tend not to have customer service centers you can call collect like the big credit card companies.

Meanwhile, I fail to see what's so dangerous about giving a kid (or your ex-wife, for that matter) a credit card. As long as the cardholder understands that all charges are his/her responsibility, I don't see what the issue is. I know plenty of 18yos for whom it doesn't matter if the card says "credit" or "debit"--they won't spend more than they have in their bank account.