I like to go with low calorie options. Dum-Dums are only 20 calories each and can last a while. The large suckers that a lot of grocery stores sell in the checkout lane are 100 calories each. Small pieces of chocolate are a good option too if you let it slowly melt in your mouth.
I recommend picking up a bunch of lolipops too. Snack on one any time you feel like having a cig, it satisfies the oral fixation. I know some people use toothpicks or stirrer straws, but I like lolipops because you can finish them like you'd finish a cig.