You can make healthier choices when you treat yourself to a tasty Starbucks (or Barnes & Noble Cafe!) beverage: ask for skim milk (I believe the default is 2%, and remember that the soy milk isn't fat free). If you want a syrup - or if the drink comes with flavors-, ask if they have the sugar-free variety. Opt out of the whip cream - painful, I know, but the drinks are still tasty!
Hot chocolates (my favorites) contain some vanilla to make them a little sweeter, so if you order one, ask for the sugar free vanilla instead of the regular. That will lower the drink's caloric count.