There are many videos on YouTube that show how you can turn empty bottles into a lamp. Thanks to Bottlelight, you can have one ready to go. It is a USB rechargeable light shaped like a cork with a bright LED that turns bottles into lamps. You can recharge it via USB. You can use your bottles indoors and outdoors. The device has a charge indicator light too.
The Bottlelight is cheap and fun. You can try one for as low as $15.