I wonder if that PBS special is still around or online?
It's definitely still available. In fact, I enjoy the show so much that talking about again got me interested in watching it again - and I'm doing that very thing now. Well, not at this second because I'm obviously typing this.
But that's only because I'm taking a break. The show is three hours long - but each hour is broken up into 8 chapters for easy viewing if one doesn't want to sit though all three hours or even just one hour in the same sitting. Anyone interested can check out
The Elegant Universe. However, the subject of parallel universes, though touched upon in the first hour, doesn't really begin in earnest until later on. So if that's all your interested in, have patience. It really does pay to watch the whole show in order to understand everything. In fact, the program is really quite fascinating - even on one's 3rd, 4th or even 20th viewing...