Dr. Seuss's works have been fodder for a few movies in recent years, including the live-action How the Grinch Stole Christmas! and Cat in the Hat (after which Seuss's widow, Audrey Geisel, voiced her displeasure and refused to allow any more live-action adaptations), and the animated Horton Hears a Who.
I remember feeling anxious about Horton, as that book was so near and dear to me, but it ended up being completely delightful. I think The Lorax could look pretty cool up on the big screen as well. And though it's a classic work (and will therefore cause some people to be outraged about an adaptation), I still find it touching that Seuss's creations will continue to inspire more generations in new ways.