I wonder if some of my friends wonder what it is I do when I'm being an at-home dad. Although I don't think anyone thinks that I'm having a grand ol' time all day every day, even I have a difficult time explaining what it is I do all day. Here's a great article responding to a person who wonders what at-home parents do.
I wanted to add something to what at-homes do, or something that I try to do:
Make sure that, when my wife gets home, she doesn't have to do anything. That dinner is almost ready. That I am presentable as is the house. That the baby is ready for love but is not crying for it.