I'm up late plenty of nights when I'm painting kid's books (often well into morning), and I notice any cravings that can't be sated by tea or warm milk tend to lean toward carbohydrates. So I try to choose healthy stuff, too.

Kashi cereal is a favorite. That stuff is so good, organic too. Popcorn is a good choice, especially since they make those nifty snack-size microwaveable packets now. Usually I make mine over the stove using olive oil, though, since my hubby isn't a big fan of microwaveable popcorn. If I'm really feeling fun, I'll throw together a small mix of popcorn, raisins or cranberries, and peanut butter chips or almonds.

If you're going to up late make sure you're still drinking plenty of water. Seriously. And take out your contacts early!