Seems like everyday some new tool to aid in playing D&D, or your other favorite RPG is published. There are a lot of map making tools available online, and random dungeon generators of varying levels of quality and usefulness.
Dungeon Map Doodler is a map making tool that is easy enough for anyone to use regardless of their drawing ability. Play with it for a few minutes and you can quickly create an interesting dungeon map for your next gaming session. It also allows you to output the map in various file formats. I particularly like the .png format, but it also has jpeg.
You can save your map to return later to work on it more, or download it.