The Cartoon Network has announced the August 13 debut of a new animated series, Foster's Home for Imaginary Friends.  The series will kick off with a 90-minute special and then, starting on August 20, assume its normal 30-minute format and time slot (7pm, ET, PT).  Created by Craig McCracken, who came up with the popular Powerpuff Girls, Foster's Home for Imaginary Friends is the story of Mac, an eight-year-old boy whose mother decides is too old for his imaginary friend Bloo.  So Mac decides reluctantly to send Bloo to Foster's Home for Imaginary Friends.  Naturally Foster's is populated with a menagerie of weird characters who are the literal manifestations of children's desires with distinct personalities and a burning desire to find another kid to befriend.