making a purchase as a "guest"

I want to give my customers a chance to purchase an item in my store without having to create an account--essentially do the transaction as a 'guest'.
What do I need to do to make the check-out process as easy as possible without forcing them to create a password and account?
Is there a "check out as a guest" option?
Thanks for your help!

They can choose to not create an account, and simply type in their information to complete the order.

The buyer just has to uncheck the "Create an account" checkbox, and they will not be required to type in a password and create an account.