This is an ultralight candle lantern that is made from a 12oz Cruiser milk bottle and a 20oz Gatorade bottle.  The candle is actually below the level of the water that is poured between the double walls.  The water layer acts as a lense to help intensify the light, and cools the inner wall of the candle chamber so that it doesn't melt and burn:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

See it on YouTube: