title: Good shopping cart gem for rails
body: <p>I need to add some functions to my app-catalog of car spare parts. I see a lot of questions on so as my. But main difference is, that i don't need something like spree gem, that also build catalog... I need to add only to my catalog shopping cart (add to cart, cart, order). Are there any good solutions? Simple cart (without e-pay systems etc)??? Becouse spree is to hard to customize (i will say to more simple it)</p>