As I am sure all of you do, I use a headlamp at night. Works great, however sometimes some ambient light that is not redirected every time I turn my head is nice to have sometimes.
There are a multitude of lightweight backpacking lanterns such as the Black Diamond orbit series. My problem with these lanterns is A) I am already carrying a headlamp and B) Most of them take 4 AAA batteries which is not something I am interested in carrying spares to for night three in the backwoods.
To solve my problem I took a lid off of a plastic Borba water bottle (no idea where it was bought, my g/f's mom saved it for me because 'it looked like something I might use for backpacking'). Anyways, I took the lid off of it, wrapped a layer of wax paper around it, then used clear packing tape to effectively wrap the lid up.
The result was perfect. The tissue paper diffuses the bright bulb enough to spread it fairly evenly throughout my entire tarp. I have used nalgenes in the past, but the clear plastic (regardless of color) fails to diffuse the light, plus I don't always carry an empty nalgene at all times. I wanted something more dedicated for the lantern purpose.
Weight is 16g
*Bonus - works perfectly as a case for my headlamp
Also Mammut makes a headlamp that actually comes with something similar.