Mechanical Engineering Mini Project Idea: Mechanical Mobile Charger

I guess I've already discussed this idea elsewhere on CE before. However, I haven't had anyone pick up this idea and develop it into a working project.

Problem: While traveling, it's very difficult to find power points where we can charge our mobiles.

Solution: This problem can be solved by having a handy, mechanical mobile charger. The handy mobile charger could have a leaver or wheel to accept mechanical energy as input and turn it into electrical energy. There could be various means of achieving this.

What do you think?