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 burrito at you yet, it might some day. 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 in the US 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]