When I flew down to Orlando in November, I asked the security folks at Akron/Canton airport to hand screen my film (which they did). I had heard horror stories about the higher power xray units that are in place at some airports. On my return flight, the security folks at Orlando REFUSED my request, saying that 200 speed film would do just fine in the xray machine.
So there you have it. The definitive "I don't know" answer. I guess the ultimate answer is to get a digital camera and be done with film once and for all.
Since they aren't xraying checked bags (yet), your best bet might be to pack you film in your suitcases.