At times my cat enjoys the Mac UI. Here she is using the Dashboard App (probably just for the weather. But if you imagine many Kitties and many Macs and all the time in the world, they certainly would have crafted designs like: Google, Twitter, and Facebook.
What you see on the left is a cat-crafted email.
She tabs through the fields. Imagine if she really focused on the user experience.
Laptops are warm and cats can click.
PS: The infinite Kitty Theorem is a reference to this