Make your subconcious work for you...record yourself talking your notes aloud and burn them to cd. Put cd on repeat while you sleep. I've never tried it before, but if it works for those loony tape therapies, it might work for studying. I'd imagine you'd have to love the sound of your own voice for it to work effectively, or your might drive yourself insane.
But no, seriously, I disagree with the all-nighter theory. For exams it doesn't work. You forget all the stuff you crammed in the night. Just read over your summaries right before you go to sleep and make sure you get a decent amount of it (6-8 hrs). Then read your notes first thing in the morning.
Now, with major assignments on the other hand, the all-nighter is a tried and true method. Strangely enough, I get the most work done between the hours of 1 AM - 4 AM.