I find that eating throughout the day and not missing meals is a great way for me to limit my snacking. I know that if i skip breakfest and dont eat until late in the day after classes I snack so much more then if i would have ate through the day. Also, like was already mentioned, only having healthy snacks around is a trick I use when I do want to snack because as least my options for snacking are healthy ones. I like to have low-fat yogart, sugar free popsicles (which are low cal and hit that sweet tooth), vegetables and fruit.