...from Wizards of the Coast, of all places. Looks like it's for 3.5, but is certainly easy to translate to older flavors of the game:
Go make a megadungeon in under 10 minutes!
And if anyone can fill me in on what the "Load" field on the bottom of the page is for, I'd appreciate it.
I've already printed out two levels, formated as booklets. Too easy!