From Wired Science:
To gamers, $40 may seem like a steep price to replace a Wii remote controller, but to scientists, a hacked Wiimote is a steal compared to the pricey sensors needed for a lot of field research.
Inspired by videos of renowned hacker Johnny Chung Lee turning the Wiimote into a finger-tracking device and a touchscreen white board, physicist Rolf Hut of of Delft University of Technology built a Wiimote wind sensor.
“It was just a bendy pole with an empty bottle on top with an LED light on the bottle,” Hut said. “And it swayed in the wind.”
The Wiimote can track just about anything: All that’s needed is an LED light. Hydrologist William Luxemburg of Delft University of Technology in the Netherlands demonstrated a hacked water-level sensor made from a Wiimote and a plastic boat at the meeting of the American Geophysical Union here Monday.
More info here.