In the thread titled "ImportedDrugs.com - India" under "Feedback based in personal experience (intīl)" when I was describing my credit card transaction with the OP, I mentioned I had used and always use a "single-use" credit card number generated by a program supplied by my bank. A couple of people indicated they had never heard of that service and ask for more information. But since general discussion of credit cards beyond the specific transaction with the OP would be off topic in that thread, I am posting my reply here.

Basically it works like this. I have programs supplied by my credit card banks (for free) that will actually generate a valid "one shot" credit card number with a maximum limit I designate. After the transaction is completed that number is canceled and therefore of no use to crooks, and the credit card limit I designate protects me from charges greater than I authorized. The charges appear on my statement absolutely normally as if I used my actual real card number. I never have to give out my real number. (and no, there is not a way you can use it without it showing up on your bill) I never spend one second worrying about who has my number.

I use it with Discovercard and MBNA Mastercard. I believe it is a common service so perhaps many other banks provide this service too. Check your banks website or call there customer service.

The Discovercard site is.
http://www2.discovercard.com/shopcenter/deskshop/main.shtml

And the MBNA site is
http://www.mbnashopsafe.com