I'm having one of those times RIGHT NOW! Stupid PMS.
This is my most suceptible time. Though my tempations to go right off plan are rare, I do feel like hoovering my way through the entire contents of my fridge and cupboards.
I combat this by eating a bit more than normal, and giving in to my cravings for salty stuff by having pepperoni, etc. I also try to ensure my fat stays up as much as possible. For instance, today I had duck and salad with olive oil for lunch, and macadamia nuts as a snack. If sugar cravings really get to me (these are getting better with time), I will give in to the diet root beer chilling in the fridge. I'll mix it with a couple ounces of heavy cream and enjoy a faux float.
I try very hard not to pacify my cravings with LC sweets, because to me that's still giving in to emotional/hormonal eating, and replacing one form of junkfood with another. I'm usually successful, but not always (hence the faux float, even though I know the aspartame will give me an almost instant headache.)
I also use the "not right now" strategy - maybe I'm the person you were referring to, Jade. I tell myself not right now, or "I'll have it tomorrow." Delaying tactics work when "never" seems too long!
One day -- and sometimes one minute or hour -- at a time!