I have heard of the thundershirt being really helpful. Some also have good success with melatonin.
http://www.wagntrain.com/independence_day.htm
And, FWIW: I'm not a Cesar Milan fan. I believe there are many trainers out there who get as good if not better results using sound, scientific principles and without magic TV editing. Flooding a dog who has fears (which is Milan's usual method) can really backfire and seldom results in long term success. His show comes with a disclaimer when it starts, that says a lot to me. I woudl recommend that you check out books and videos from Patricia McConnell, Jean Donaldson, Karen Pryor and Ian Dunbar.