Virtual Account Numbers
Elliotte Rusty Harold has a bit on Citibank's virtual account numbers. This is a great service I've been using at MBNA for several years now.
One thing he doesn't mention is that in addition to making a "one-time-use" credit card number, you can specify a maximum credit line and an expiration date.
Here's what it looks like on MBNA when you choose the credit limit and expiration date. This way you know that not only can only one person charge the card, but that they can't exceed the amount you actually bought.
They do have some bits in the terms of service about how they have the right to extend the credit limit by a small amount to account for sales tax and shipping charges, but you can be sure that they'll refuse a charge that is significantly higher than you specify.
tags: virtual account numbers, credit cards