IMAX is getting even bigger, says the NY Times, clipped from last week:

LOS ANGELES, Sept. 15 — A flame-spewing rocket fills the theater's six-story screen, not quite life size but close enough for discomfort, its roars and rumbles shaking the high-back seats and vibrating the concrete superstructure. "How about that?" asked the producer Brian Grazer. Imax, the maker of giant-screen film-projection systems that has hobbled along for three decades on a steady diet of natural wonders and scientific dazzle, never quite able to convince Hollywood to adopt its humongous but cumbersome format, says it has developed a new technical process that can transform existing 35-millimeter movies into bigger, more vivid 70-millimeter Imax experiences.
http://www.nytimes.com/2002/09/16/movies/16IMAX.html