Popular UIs is a resource for free popular web UIs reproduced exactly in Photoshop for educational purposes. It's a small side-project I've been working on, and there's more to come soon! Check it out and download Facebook's Timeline and Apple's Bento Box UIs!
If you'd like to contribute a UI, send me a message!
Click Like and help me spread the word!
Update: Sorry, some of the resources 500'd, so I've switched them over to S3 now.