Just got a Touchpad for my daughter for her birthday (age 12) and setup her own WebOS login. I'd like to allow her to buy some apps for things she would like, but limit it somehow. To make purchases through the App store you need to setup a credit card number but I want to be able to manage it so she isn't just buying things to buy them. Is there a way to purchase on a account say $20 in advance that she can use to buy apps however she wants. Sort of a coupon or credit that would applied to her login. thanks..