announcing
depends on if this is the first and if they were planning it..
my first kid, my husband was right there with me and the stick!
the second kid, not planned...and i had a suspicion and checked it....our fist was 1 1/2, so i had a little shirt made for him with primary letters ironed on in "caddywampus" child-like writing that said,
"I'm going to be a big brother!" i was trying to hold out until father's day for my son to wear it, but i couldn't stand the wait and revealed a few days before.
(we then had a family barbecue with his parents and my parents and had our son wear the shirt again.)
this is how we shared our first pregnancy with our parents:
my husband owns and runs a restaurant, so we invited them all to dinner and had a mock special of the day printed on the insert (just their menus, not the whole restaurant) entitled "Grandparent's Delight" and it said something about babysitting opportunities and a few other things...read just like an actual entree.
you could (or your friend) make a fake candy bar wrapper or Gatorade....or tie it into something the father likes/does.