My DD has had a Visa Buxx for the last 5 years and has had NO trouble using them at WDW. A friend of hers had one and we decided to get one for DD before her 8th grade trip.
It worked great. We made sure she had enough money on it so that she would not be worried about carrying too much cash. She did have some for meals, but for all her souveniers, she used her Visa.
She has even used it on other trips and around town. (She has used it at our Target with never a problem-could be certain banks). I put $20 a payday on it and that is her allowance. She knows when the money is going on and keeps track of her balance, so that she knows just what she can or can't get depending on her balance.
It's a great way to learn how to use a credit card for teens. They have to know how much "credit" they have to be able to use it for purchases. Their "credit limit" is the available balance-cash on the card. The only difference is, they don't pay a bill at the end of the month, it is already paid for in advance.
Wachovia Visa Buxx is pretty good. You can do a search on google for Visa Buxx and it will give you a couple different banks that have them. But check the load fees - fee to put money on the card. Some have a fee for each time you put money on it, some don't. Wachovia doesn't.
My DD is now 18 and DH is thinking about getting her a regular credit card with a low credit limit, so that she will learn the responsibility of making the payments.
One other thing about the Visa Buxx, it allows others (relatives) to load cash gifts on to it too. You can set it up to allow relatives that option. A parent does have to have their name on the account too. I get a statement of my DD's account activity monthly just like she does. So I know where her money goes to (I usually do anyway).
I was truly glad to find out about Visa Buxx. It has made her traveling out of state so much easier. I know she has enough money but she is not carrying cash. Plus if she is out of town and needs more, I can always add it and she will have it right away.