WTF? Why would corn be prohibited on South Beach? I've heard nothing but negative things about that "diet."
An ear of corn on the cob is one Weight Watchers point. I get 26 to spend every day. It's a pretty awesome system if you stick to it, and I know so many people that it works for.
You're only supposed to avoid it during the first 2 weeks of the diet. It's just got a lot of carbs, and the first two weeks are very Atkins-like. I'm going back on the strict phase because I've gained about 15 pounds back. I have enjoyed eating what I like, but the french fries and sugary foods will make you gain weight, no matter what diet you're on.
I still eat sweetcorn now and then. I just can't eat anything else with carbs that day. But it's worth it.
In fact, even when I'm not strictly working to limit carbs, I'm still keeping my intake much lower and I've been able to maintain 20 of the 30 lbs I lost a couple years ago.