jssCart is a great javascript shopping cart that is super easy to setup, install, and customize.

Check out these features:

• Easy Installation
• Easy Management
• Accept Credit Cards and/or Paypal
• Includeable into any web template
• Full shopping cart features in 3 html pages
• No page loading for in-page action
• All code is fully customizable
• No database required
• Html pages for all products

Coming soon:

• Stock and quantity
• Product categories
• Multiple Product Pages
• Integrated Gateways