One of the most common and regular warnings that we get on our cellphone is “Low battery!”. If unfortunately, the charger is not with us then we tend to borrow it from somebody or search for a charging point. If we are even more unfortunate then we have to stay paralytic till we get it going as the phone dies.
Think of a way by which you could charge your cellphone by using energy from something you primarily use your cellphone for. You talk!!! Look at this: Talk-powered cell phones? Nanoscale piezoelectrics could make it real http://www.networkworld.com/community/node/35879