Herbal Tea: a cup can give you that warm, soothing, filling feeling & the calorie content is a magical 0!
Almonds: They are portable, no need to refridgerate, and they have that crunch that makes you feel full. They also have been known to increase your BMR (basal metabolic rate), which means they can increase the calories you burn at rest.
Protein Shakes: Very convenient for a busy person on the go, whey protein shakes, (the clean kind, without those artificial sweetners and other chemical crap - go to Whole Foods, you will find the best type of protein available, all natural!!!!) as part of a higher protein diet (to help you recover when you workout), have been shown to help melt away body fat better than a high-carbohydrate diet after 12 weeks. Remember though, protein shakes are not a substitute for real, whole foods that give you the vitamins, minerals and nutrients your body needs. Use them as a supplement, not a food replacement.