Opinions on the checkout process, anyone?

[eluser]slowgary[/eluser]
I plan to store the user's information from paypal IPN either way, as I'd like to be able to send promo emails or postcards, plus if I ever need to reference an order.

I probably won't make suggestions because I won't require an account or login, so while a user is shopping I won't know of their past purchases. The 'Agree with Ts & Cs' is a good idea. I just don't know if I should take it a step further. Maybe people would like to be able to recall their own orders?

I prefer to not have to 'sign up' for every site I buy something from, but at the same time I like the ability to recall past orders. Just not sure which route to take.