Wraparound segments for ABC's Saturday-morning children's series. Elements of "One Saturday Morning" include: "Great Minds Think For Themselves" (Robin Williams, in a reprise of his Genie role in Disney's animated film "Aladdin," offers his take on famous historical figures); "Manny the Uncanny" (an inquisitive character who goes out into the world to see what people are doing); "The Monkey Boys" (Hodge-Podge and Buddy combine physical humor and toony logic to produce a live-action cartoon); "Mrs. Munger's Class" (animating the mouths of typical sixth-grade class pictures, students interact with each other and their teacher, carrying on outlandish conversations); "What's Up With That?" (a young professor offers quick, informative facts); and "Tube Dweller's" (follows the antics of maintenance men Bob and Bob as they dawdle behind your screen).New cast members for the 1999-2000 season include: Miss Moose, the mascot; Millie, the message lady; and the musical group, Roller Toasters. New segments include: "Cafeteria," a musical take on conversations that take place on a school cafeteria line; "What's the Diff?," an animation segment that challenges kids to tell two very similar-looking "snapshots" apart; and "Find Out Why," an animated segment hosted by "The Lion King's" Timon and Pumbaa, which explains a variety of scientific occurrences and commonplace technologies, including rain, sneezing, static electricity, wind, airplane flight, etc.