FYI for those planning on getting disposable cards, you might want to(although more work) look into a card that can change the number when you make a purchase. You just have to login to your bank account and request a 1-time use number. The reason is, prepaid cards sometimes have issues with online merchants due to the billing address and some online places disallow them, especially if it requires a recurring charge, or 'free-trial for 30 days' and you just have to give them a card on file.
Paypal offers this with their debit card, and I think it was citibank that also has it.
Paypal offers this with their debit card, and I think it was citibank that also has it.