Empty soda bottle (Fallout 3)

The  is a clear glass bottle in Fallout 3 and Fallout: New Vegas.

Fallout 3
The empty soda bottle only serves as a common form of Rock-It Launcher ammunition.

Fallout: New Vegas
You can squeeze the water out of three Prickly pear fruits into an empty soda bottle to form a bottle of Purified Water which essentially is Cactus water.

Locations
There are four in Goodsprings gas station where Ringo hides.