The Star Wars thing was a fun day. An insane, and I dare say possibly rather pathetic thing to have wasted an entire day on, but it was certainly memorable - aided by the fact Lucas himself and some of the cast came over from the Sith premiere happening across the road to introduce EpIII to us before we got to see it (the viewing order of the day went IV, V, VI, I, II, III which is actually the best way to watch them in my opinion). It was at the Empire cinema in Leicester Square which is a comfortable cinema to be in though the whole event kicked off at around 7am and we were not out of there until about 10:30pm. There were breaks of course.
It only became unbearable when Episode II began partly because most where by that point anxious for EpIII, but mostly because Clones really is a dreadful movie and watching it alongside the other five to me - really showed it up to be the worst of the bunch. That said, the prequels were far more tolerable amongst a mass of fans than they are with a quieter audience or at home. After so many horrible tweaks and changes to the classic trilogy and the insipid scripting of the more recent films I have to say the whole event did serve as a good opportunity to finally phase Star Wars from my life given the fact I'll probably never get to own the classic trilogy in their original form and view them in the quality they deserve at home.
In America before Return of the King opened they showed the extended editions of Fellowship and Towers back to back before showing King (theatrical cut, obviously). I know a few people who attended those events. I'll say one thing about the LOTR trilogy, Two Towers in both its theatrical and extended forms does become somewhat of a chore halfway through where they really lost a sense of what they should be focusing on. The editing and structure really gets a little sloppy. They do admit that on the commentary tracks mind you blaming themselves for getting too caught up in Fellowship promotion when they should have been smoothing out the second film. Still, it's amusing and testament to the film's astonishing achievement when one could perhaps dub Two Towers the “worst” of the trilogy when it is still a remarkable spectacle to behold in its own right.