As strange as it might sound, "Phineas and Ferb" is a showcase of effective use of a cutaway. In fact, that show wouldn't function without it. You've got the main storyline (Phineas and Ferb inventing something) running parallel with the secondary plotline (Perry the Platypus foiling the evil Dr. Doofenshmirtz). Those two plotlines impact each other in ways the characters aren't aware, but the audience knows what is going down thanks to the clever use of cutaways.
Watch the show yourself sometime to see how that works. Hey, it's a kids show but the use of cutaways is downright brilliant.