For the last semsetr I've been out fo college and still running a game there we've basicly gone with the all night session as our standard MO. I have a 4 hour drive to run the game, so I can only make it every other weekend and we typicaly have a lot of ground to cover (only one day gets devoted to D&D, since this is teally the only time I see my friends). Start after brunch around 2 and run the game until one of the players passes out, typicaly 8-10 AM the next day.
I have no clue what it takes to do this, though. It's nearly 5AM now and I'm here posting. My motto's always been sleep is for the weak. (Though I prefer my freidns "Ill sleep when I'm dead these days")
The other players typicaly break off and grab som soda / snacks around 4am, which I've found to be a good idea, just because DMing makes me thirsty.