Really Good UX - A library of screenshots for UX inspiration
UX Challenges - Done reading about UX? Start doing it.
Startup Timelines - How the frontpages of famous startups changed over time
Uxcel - The easiest way to learn UX/UI design
UXTesting - Discover how your mobile users feel
uxtoast: Learn UX Design - Become familiar with design laws and learn how to use them.