I use prepaid cards all the time. I had my identity stolen a couple of years ago by a waitress in a restaurant we frequented. Luckily it was caught quickly and resolved, but needless to say I am paranoid about CC use now. I usually only like to use them in places I swipe it myself, and never ever online. I buy the prepaid cards for online purchases.
When you buy it, the cost is $10, and you can choose either MC or Visa. You tell the cashier how much to load it waith, say, $50. So the total purchase is $60. You get a printout with a PIN number. You then call or go online to activate the card. You give info such as name, address, etc.. you can use the card online instantly, but it takes about 10 days to get your plastic card in the mail. After you get your plastic card you can reload it anytime for $5 per load (you have to lead at least $25- I usually do $100-200). The card can be loaded with up to $10,000. You can also get a card for your significant other or child that uses the same account. I LOVE pre paid cards. OH! and they charge $5 a month service fee.
I like them b/c I know not much damage can be done if someone gets hold of the card or number. It can also help you stay on budget for certain things such as Christmas shopping

. You can also get them replaced like a regular card if they are stolen/lost.
I'm wondering about the CC ADRs.. if I want to reserve 4 restaurants, will I have to load enough money to cover the cost of those meals, or do I just need an active card with some money on it? Do they charge for the meal when you make the ADR?? Also, we are going in Feb, and we have the Deluxe Dining Plan, if that makes a difference.