For the final week of a group project at university, the project members and I ended up staying in the computer labs pretty much for 5 days. Another project group did the same (to this day we're still good friends). Everyone brought in their PCs from home and we ended up sleeping in the labs overnight. None of us went to classes as it was pretty full on crunch time to get the project done.

When it was time to eat, we each took turns to go on a food run for everyone, like getting McDonalds, or getting everyone coffee or energy drinks. Of course it wasn't all just work. At the time Quake 4 was just released and we had some pretty epic matches at 3am.