Oh man. I tried to stay out of this thread but I just can't stand it anymore...
NONE of the movies mentioned in this thread are good examples of fencing or kendo or any other REAL sport derived from sword fighting. I've NEVER seen a movie that was totally accurate to "real" sword fighting & I've watched a lot of movies that have sword fights. Even in movies that try to be accurate, you inevitably see at least a little bit of artistic license taken to add flourishes that, while they would never work in real life, look good on screen. And Gladiator? Please! That movie features Russell Crowe swinging a gladius around like a cavalry saber. The Roman gladius was designed to do ONE thing: stab at enemies from behind the protection of a huge frickin roman shield. It doesn't have the length or mass to develop the power needed to do something like...say... behead somebody.
And I'm sorry but "training in sword play"? I took olympic fencing lessons for 3 years in college and I've practiced traditional Japanese kendo for about 4 years. I can't imagine hearing anyone I've trained with call it "sword play". They are sports. They are derived from fighting techniques that were originally designed for military combat. In the case of kendo, it's been a steady unbroken evolution over hundreds of years from military training and practice that become obsolete into a sport, which is really cool; but today it is still nothing but a sport.
As for the swordfights in Star Wars, the short answer is this. In the OT, the fighting techniques were derived from European fencing AND Japanese kendo. Nothing seen onscreen actually looks like real fencing or kendo, but it is clearly derived from it. Both of these fencing styles use attack techniques that focus on and follow straight lines, meaning you move directly towards your opponent and strike directly.
In the prequels, there was a shift to more chinese styled techniques. Many chinese martial arts focus on circular motion, resulting in all the spinning and such. It looks VERY different (obviously).
As for the twirling the lightsabers? That's just cheap baton twirling to look fancy for ignorant people who don't realize that all it does is make a HUGE frickin opening for your oppenent to attack and kill you.... (I'd LOVE to see someone to try that in kendo! even a beginner would mop the floor with them.)
EDIT:
For anyone interested, here's a pretty good video showing about as close as you can get to a "real" sword fight these days. It's highlights from the 2007 All Japan Kendo Championship. These guys are REALLY good. & the video shows lots of cool slow-mo stuff so you can actually see what's happening.