PayPal appears to be borrowing some design elements from Nike in a mockup on its own website.
Over the weekend, I noticed an image of two "your cart" designs side by side -- one PayPal, one Nike.The similarities are rather, uh, remarkable.
Scratch that. They're almost exactly identical, top to bottom.
The left image is a mockup of a checkout cart that PayPal is using all over its own website -- you can spot it here, here, and here.
Now here is a screencap I just took of Nike's current cart -- including a pair of shoes that I do not intend to buy.
In all likelihood, a designer at PayPal needed a solid example of a checkout cart -- probably on a tight deadline.
Whether it's a mockup or an actively used part of the checkout process is beside the point. PayPal is promoting its services using design taken wholesale from Nike, and I'll bet you anything Nike paid R/GA a pile of money for it.
Unless, of course, there exists some under-the-table design sharing network. Or maybe Nike's website design is free for reuse under Creative Commons.
Neither PayPal nor Nike immediately responded to requests for comment.
UPDATE: A representative from PayPal replied, saying "We are constantly testing new design ideas and the one you saw was just a test. We collaborate with Nike, value them as a merchant and respect their design perspective."