Are there any "devices" that can be used to make on-line purchases like a credit or debit card but which will never have an attached line of credit? In particular what I want is a card that, when the balance goes down to zero, further transactions will be declined rather than result in an overdraft.
A while back, I asked a few banks about this and they said that their debit cards did this except in the case where I had agreed to a contract allowing some third party (e.g. PayPal, NetFlix) to charge my bill on the card. This is a problem for me because this is the exact case I'm wanting such an account for.