Ideas to announce to family!?

I am a little over 5 weeks with and EDD of early December, hubby and I originally wanted to wait until after our first ultrasound to tell the family and close friends. However my dad, who lives out of state is coming to visit 2 weeks before my appointment. We are having the immediate family over for dinner and I want to do something cute and special as this is our first and the first grand-baby. Thoughts/ ideas? Ready go!