Having shown with multimeter that we could get about half a volt from the cell, we made a battery of 8 of them to try to power an LED. Naturally once that worked it we tried something a little more taxing.
Impressively it managed to power both the LEDs and the PIC microcontroller. Though whether this says more about the microcontroller than our battery I don't know!
Brief Notes on making the battery:
Cut and strip lots of tiny lengths of wire.
Attach a zinc plated screw to one end, and tape a penny to the other (for all the wires you have).
Get a screw organiser box (or something with lots of small compartments) and fill with salt water.
Finally connect all the compartments one by one so that each has a wire and penny going in, and a screw and wire going out (in a chain). Support the wires, (I used cardboard with scissors cuts) so that the connecting wires in each cell are not touching the water.
The battery combines a load of cells thus it can produce a serviceable voltage. Try varying the materials used for anodes/cathodes (and perhaps think about another electrolyte too) - for greater potential difference and longevity. As I remember zinc and brass stuck in a lemon (or potato) also works - and is perhaps a little less messy.
A page from James David Chapman's website.
Located at: http://www.users.globalnet.co.uk/~jchap/
Site mirrored here at: http://www.j.chap.btinternet.co.uk
Battery
