The original OLPC attempted to ship a pull-cord generator. Trevor Bayliss, of Freeplay radio fame, proposed a generator based on hoisting a weight on a branch of a tree. The principle is sound.
As for taking money from locals, I would be surprised if kerosene was produced locally... and even if it was, this is a one-time expense, versus an ongoing outlay.
I worked at OLPC. We didn't ship any kinetic charging systems as the most reliable ones had a mean time to failure on the order of ~three full charges. The scheme was cute and captured the imagination of people in the developed west but is fundamentally unsound due to the cost of high precision, reliable manual chargers and their miniscule power output. In addition to yielding only several full charges before the $50 charging unit failed, each charge would require tens of thousands of revolutions of a hand crank. As wonderful as the laptop was I think it would be a very strange thing for a child to do when they could easily play with something more immediate.
In practice most of the laptops are charged like other laptops--- from national power grids. Those that aren't are charged from diesel generators and solar power.
