YouTube 1980
Go to YouTube, choose a video, pause it, type 1980 (not in the search bar) and hit play.
LetterBug - Send A Letter Without Leaving Your Chair
Consdering how rarely you actually have to send a physical letter nowadays, LetterBug is a pretty handy site that is similar to online greeting card services, only this time, it's just a letter.
Earl's Court Police Telephone Box
Super easter egg in Google Maps. Make sure you're looking at the police box, and click the middle arrow.
Via Empire Magazine.