I'm designing a site and need a very simple shopping cart. I'd like to be able to make a button/link for a product, keep track of the number of products ordered, remove, update. No user login, no order tracking or anything like that. I like solutions like RomanCart as they allow you to make a button/link for a product and their cart keeps track of it. As basic as it gets. The only problem is that RomanCart and other cart providers are hosted on their own servers. Our payment provider is obviously hosted on their own site. So suddenly it feels like our site's functionality is spread across three separate domains. Doesn't feel neat or look very proffesional. Any ideas of any free, very basic shopping carts?