I had a little party for him. Bascially we just invited Daddy's and my friends, so that all the uncles and aunties could play with him. And invited 3 other babies.
My baby actually enjoyed it very much! I think it's really important he can look at the pictures when he's older and say, "Wow, what a party mommy had for me!"
I made a huge poster with pictures of him in the middle, and asked everyone to sign something for him. He'll look at it and understand when he's older.