Generally, it's a bad idea. It keeps the craving cycle going. The only way to get rid of the cravings is to go cold turkey and ride it out. Even diet soda can keep the cravings going. Anything with artificial sweeteners can.

Having said that, I still drink diet soda because it doesn't seem to affect me, but I think I'm in the minority.

If you truly are hungry, remember to go ahead and eat. Eat a protein snack, and be sure to be getting enough fat to be satisfied.