*Mintjulia
People who ring, leave a message and then keep ringing every 45 seconds.
If I haven't answered the phone, there is a reason - I'm driving or in the shower or making pastry and my hands are covered in gunk. Just go away and do something else, I'll call back when I'm not busy.*
This is what my MIL used to do, right in the middle of our DDs' bedtime routine. She justified it by saying that she was worried that my DH hadn't yet rung back (after 10 minutes).