http://www.ebay.com/ General Retail 1-Page 120 seconds
Ebay has a single-page checkout. It does provide an option for a guest checkout, but it must be selected on the login page and is not the default checkout. Having shipping address and shipping selection and payment on the same page leads to a shorter checkout.
The header/navigation is removed throughout the checkout, reducing distractions that can lead to cart abandons. There are also no distracting up-sells in the checkout. Forms are well-organized, but could be made more intuitive by adding autopopulated addresses, a prominent help option, and minimizing the size of the gift card area.
NOTE: Our analysis applies primarily to Ebay's normal purchases - the auction side of their website is a different situation.
The Ebay Desktop Checkout complies with 73% of our recommended best practices.