Brett,
You can try contacting Tailwaters flyshop in Dallas. Within the last month or so they had Lefty there for a seminar/book signing. They have also had Flip Pallot. He could be slated for another one soon. But if you are going to be in Dallas and are in need of casting lessons, you do not necessarily have to get them from Lefty. I can think of at least five FFF CCIs right now, all of which, I would imagine, would be infinately cheaper than Lefty.
Also, if you are going to go the TFO route, and this may be unorthodox, but see if you can get some time with Rick Pope, TFO president. He has shown me things that books and countless DVDs probably could not have. I have never met a better caster or one whom understands the workings of a rod/line better.
Dusty