Huh, never heard of them before. Interesting concept, but the in-browser replacements worry me. Know of any service that does disposable CCs without the in-browser hackery?
Citbank offers disposable credit card numbers for your account:
I believe you, but I would much prefer not to have another credit cards. I have a very straightforward system right now, and adding a citi card would not help that.
Some banks also have virtual CCs included.
I used this back when PayPal did it. Wonder why they stopped.