I have so many friends right now who are expecting - I would make buttons for all of my pregnant friends that they could wear depending on what type of mood they are in and where they are going. They would say things like "Don't touch the belly" or "Yes, there's a baby in there" (for that weird in between is-she-gaining-weight-or-is-she-pregnant stage) or "i gave up coffee for this" or (even better) " i gave up drinking for this?" or "don't ask the name's a secret"
Thanks to everyone who submitted! So many great ideas made it nearly impossible to pick just one!