Shake That Cellphone, Shake It!

From New Scientist:

Need to make a call but run out of juice? Just give your cellphone a shake for an extra burst of power - that's the idea behind a new cellphone charger that turns movement into energy. Shashank Priya and his colleagues at Virginia Tech in Blacksburg are designing an emergency onboard charger that draws energy from the piezoelectric force generated by your fingertips clicking the keypad, your voice - or just by giving the phone a good old shake.