How to make the World’s Cheapest PDA for free?

This is the world’s cheapest PDA that you can ever get! It doesn’t need any batteries or a charger, doesn’t break if it falls down, it’s super light-weight and you can have more than one, almost free. So, make this gadget, which saves 100% electricity, doesn’t need a recharge, fits perfectly in your pocket, and doesn’t cost more than a few pennies.