For 50 years, Alvin and the Chipmunks have been driving parents nuts with their helium-infused banter and shrill bastardizations of pop music. Now, in their third movie, the rowdy rodents add to their own squeals the voices of three chick-munks, their back-up singers, the "Chipettes." As world famous recording stars, they're off on a cruise, but Alvin, an incorrigible troublemaker, pisses off the ship's captain, and then, through derring-do and colossal stupidity, gets the 'munks marooned on an island. And so once again it's up to Dave (Jason Lee), their manager/caretaker, to save their striped hides. Lady Gaga and the Go-Go's add their voices, and David Cross and Jenny Slate — as a failed record exec and nutjob castaway, respectively — contribute to the rat race. But overall, Mike Mitchell's assault will appeal only to the under-10 set and send everyone else running for ear plugs.