Well, I'm at least keeping this tradition alive as long as I can. If the Muppets can celebrate unity and diversity on a regular basis, then we can do the same thing, even if just for one minute a year.
Ringing bells in the theater? Well, when I went to see Harry Potter and the Deathly Hallows Part II, there were a bunch of people in the audience who raised wands and yelled "Mischief managed!" when the film was over. Bells might confuse some people, but hey, it's up to you how you want to celebrate.