On the Gawker MP...I know no one will see my comment if I leave it over there, but I thought it might amuse you all to know that this happened to me when I was in preschool.
My best friend at the time (we were toddlers) and I have similar names (the first syllables are the same), we were both blondish with curly hair and round faces. Both our fathers are about six foot three with glasses, beards, and gray hair. The dads both picked up the wrong kids from school and the mix up didn't get discovered until the moms intervened.
This probably probably explains a lot about me, doesn't it?