Couple of months ago on a group programming competition ( one computer - three people). You write your code, if it doesn't work, you print it and another person sits at the computer to write your code and you munch on yours on a piece of paper.
Maybe it's a bit off topic here, but we also saw it was sometimes more productive to do it like this with the physicality of the paper and pen. You can doodle, or visualize data right on the margin.
Still I think it's only usefull in such "academic" problems. You cannot possibly do it with a multi-file, >1k SLOC project.