A common dieting tip also works well for keeping eating light at night - brush your teeth right after dinner. You're much less likely to snack and disrupt your digestion.
well in my region the southern Mediterranean it is common to eat dinner late in the evening after 9 and especially in the summer month.
I'm betting timgray is in the US though, and you in the med are also having a sieasa and are staying up til midnight or later easily, and generally it was still to warm/lively to go to bed @ 9pm anyway!
And if you're the type of person who needs to wear retainers every so often to keep your teeth in line, slap 'em on after your last meal of the day. Works wonders for me :D
I'd leave it fifteen minutes - when you eat you release enzymes which soften the enamel on your teeth. By brushing straight after eating, your teeth will be weak so over a long period of time you could damage them.
While I agree that you shouldn't keep snacking up until you go to bed, the distinction should be made that snacking frequently doesn't "disrupt" your digestion, as the digestive process requires no "rest phase" in which food shouldn't be consumed. It is also a myth that eating before bed can keep you awake (assuming the food does not contain high concentrations of stimulants or sugars and does not cause nausea/heartburn), as the digestive process works just as well during sleep and does not interrupt the transition from wakefulness to sleep.