Prepaid Credit Cards
These are basically an alternative to cash. If you load up your card with an amount then it's safer to carry about than to carry a load of cash with you.
You can also load it up from your business account or even other accounts such as paypal.
Some people use this method to avoid paying tax on their earnings by loading it onto a card and then spending that money on persoanl stuff or/and just withdrawing it from a cash machine.
Prepaid cards usually cost a small administration fee to get them. You will get charged every time you load the card up, and you will get charged if you use it to draw money out of an ATM.
You can also give this card your children knowing that there is a set amount of money on the card.
Children quite often use a similar method to purchase their food from school these days - it works in much the same way as that.