Prepaid cards work just like credit cards, but you put the money on the card before you use it. You do not borrow money like a credit card. So what are some of the best uses for the prepaid ones? Prepaid cards can be given as gifts. Ever get a gift card for Christmas? What if you do not want anything from the store that you got the gift certificate from? With a prepaid debt version you can spend the money anywhere, this makes it a much better gift.
You can also use your prepaid version to buy items from online merchants. You may not feel comfortable getting a credit card, but with a prepaid one you have perfect control over how much money is on the card and you do not have to worry about paying anyone back, or paying interest.
Another thing you can use your prepaid one for is to pay for everyday items that you do not have cash for. It's not safe to carry large amounts of cash on you, but a prepaid card can be turned off in case it is lost or stolen.
Use prepaid ones to separate your spending. If you only want to spend a preset amount of money on your day to day spending on coffee or alcohol or whatever it is you want to keep under control, only put the budgeted amount on the card. That way once your card stops working, you hit your budget. This will help you develop budget discipline.