I'm a student and I recently started dieting.
My diet is basically a meal at 12 Noon then another meal at 9ish PM w/ some Mag10 type protein supplement "pulses" in between.
SO...to avoid sitting around thinking about food, if I'm not in class I just go to the cafe down the street to do homework/study/whatever...I only bring enough cash for a cup of coffee or something - that way I can't buy any food unless I decide to walk back home.
This technique is great - I do WAY more schoolwork, I'm not always thinking about food, and I'm out of the house more.
Also, to parrot what Stu said, I chew around 1 pack of Extra gum a day lol...And sometimes I'll literally plow through 2 or 3 romaine hearts in one sitting to satisfy cravings. I also drink double gulps from 7-11...Perhaps not the healthiest choice, but I'm not eating kcals, and thats what my diet calls for...