"Horton Hears a Who" will entertain both children and adults alike. The animation is engaging, and I enjoyed the character designs, and the overall environments of Horton and his pals, and of Whoville. Jim Carrey voiced Horton, the kind-hearted elephant who thinks he hears voices coming from a small particle that holds the entire Whoville universe, and ends up conversing with the mayor of Whoville (voiced by Steve Carell). Carrey does a fine job imbuing Horton with a sense of wonder and self-deprecation that makes him lovable and fun to watch, plus the animation of Horton is also very entertaining in most scenes. The Who's are given equal time for the audience to get a glimpse into Whoville life, and some slapstick comedy bits are provided through the daily grind that is the mayor's life. Horton becomes protective of Whoville, using a dandelion to host the particle, and wanted to find a safe spot for Whoville, but there is always the doubters of Horton's story, and they will stop at nothing to discredit Horton, lest he convinces the children (of other cute animal characters) of the implausible existence of Whoville. Overall, it was a fun movie, maybe about 5-10 minutes too long, but otherwise, a very enjoyable tale for all ages. I give it 3 stars, or a grade of B.