For the time being, I'm going to be using Paypal (http://www.paypal.com). I'm not 100% sure about them, but it's fast, easy and secure - and I don't have to fool around with any credit card info. If you've got comments about them, drop me a line at firstname.lastname@example.org.
Remember, these little dudes cost $12 +tax and ~3 bucks to cover shipping and handling. I'm trying to get you out-the-door for under $20, because I love you.
Choose your color and give your newest little friend a name (leave the name field blank and I'll choose one for you).