One of the first first person UI apps to go live in the iPhone AppStore. Nearest Tube tells Londoners where their nearest tube station is via their iPhone's video function.
When you load the app, holding it flat, all 13 lines of the London underground are displayed in coloured arrows. By tilting the phone upwards, you will see the nearest stations: what direction they are in relation to your location, how many kilometres and miles away they are and what tube lines they are on. If you continue to tilt the phone upwards, you will see stations further away, as stacked icons. Thanks for the tip Julian!