I feel your pain!
Ice cream is my ULTIMATE weakness....
unfortunately, my rail-thin sister loves it so it's always in the house, despite my compliants...
Anyways, you said you already use the mini-ice cream cones...
just fill it to the top of the cone, no blob on top and that keeps it to like 50 cal and less than 1 gram of fat....
(with frozen yogurt at least)
also, for a healthy spin on things, if you go to any health food store they have these "Soy Dream" bars that honestly taste EXACTLY like "normal" ice cream, plus they have soy protein and all that... still about 100 cal and 2g fat or less but they're a nice change....
aaaaand... if you know you're going to have ice cream, maybe try it as an after-lunch thing... more time left in the day to burn it off, etc... or just make sure you're really good all day and use it as a reward..... ie: if you eat all your veggies and drink all your water, THEN and ONLY then can you have your treat
good luck!!!