Wired on a location-based game at the Tower of London.
Through a thick drizzle I gaze at the ominous gray stone buildings of the Tower of London, England's most notorious prison. I wander from one to the next, trying to imagine what it was like to be held captive here hundreds of years ago. That's when I hear a ghost. "Psst, you there… I'm sentenced to die tomorrow morning. Please, I beg you, can you help me escape?" I stop walking and look down at the screen of my HP iPAQ. There's a picture of a portly Brit in 18th-century garb. His name is Lord Nithsdale, and he was involved in a plot to overthrow King George I. In my earphones, the voice tells me I've entered the year 1716 and again asks if I want to play the Lord Nithsdale adventure. I wipe the raindrops off the clear plastic pouch holding the PDA, a GPS unit, and a radio transmitter and hit Yes.
The adventure is part of a prototype location-based game designed for visitors to the tower, where inmates like Guy Fawkes and two of Henry VIII's wives were executed. The idea is that instead of reading plaques and staring solemnly at the Bloody Tower, tourists skulk around with PDAs, re-creating classic prison breaks.
These historically accurate scenarios were created by the charity group Historic Royal Palaces, working with Hewlett-Packard and using software developed by HP Labs. The free app lets anyone layer a virtual landscape — what HP calls a mediascape — over real-word terrain using maps and GPS coordinates. Audio and visual media can be triggered by a user's location or by sensors that detect proximity, light, heat, trajectory, and even heart rate.