Rodney said:
Don't forgot XL and XXL

Lots of t-shirt lovers wear bigger sizes.
Welcome to the T-Shirt Forums! I think your site is the first t-shirt site (besides t-shirts.com) that I've seen use Google Checkout. How do you like it?
thanks for the comment. I don't think I will be printing XL and XXL any time soon. I have very limited resources so I'll start with the most common sizes and maybe later on add these sizes.
As for Google checkout, it's good, I like it. It takes not too long to set up (same as PayPal) plus it has API and I actually got it to work, but during the setup process I had a few errors so Google suspended my account for less then a day, and I went back to manually entering items on the checkout backend. I'll use that for now while I don't have too many items, and then I'll finish their API in PHP.
So yeah, try it if you want. Also, forgot to mention, because I use AdWords on same account and spend few hundred bucks a month on ads (for a different website), I get this amout times 10 free purchases processing, so Google waves all processing fees while I'm under that amount.