Remember the Tacocopter, that delicious hoax? Thought that may not have been real, the Burrito Bomber is, and though it may not be able to bomb a burritos at you yet, maybe someday it will. After all, the onslaught of food drones is pretty much inevitable.
Developed by Darwin Aerospace, the Buritto Bomber is completely open-source and mostly made from things you can get your hands on, so you could (theoretically) build your own. The body is a SkyWalker X8 Flying Wing, it flies using Ardupilot and drops its mail-tube burrito bombs using a Quantum RTR Bomb System. The drop-site is designated by app, and the drone can either make the run autonomously or with manual steering if you want to take a ride.
Unfortunately commercial use of the Burrito Bomber or any food drone is illegal right now due to restrictions by the FAA but that could change in 2015. That's a long time to wait for a burrito though. You might be better off buying one the old-fashioned way and just throwing it up in the air. Or, you know, eating it. [Darwin Aerospace via Reddit]