Really Good UX - A library of screenshots for UX inspiration
Culture Codes - Company culture decks aggregated all in one place
Startup Timelines - How the frontpages of famous startups changed over time
Culture Your Culture - Finally, the much needed step-by-step "how to" for culture
UXTesting - Discover how your mobile users feel
Tettra - Tettra is a company wiki that helps teams manage and share organizational knowledge.