You can buy several plain white onesies and fabric paints and allow each guest to decorate one onsie for the new baby.
Get a piggy bank in the shape of a zoo animal, and at the begining of the shower give everyone a name tag with a baby item on it (bib, stroller, bottle, etc.) Let everyone know that these baby items are their names for the shower. If anyone is caught calling someone by their real name, then they have to put loose change or bills in the bank, any amount is ok. Make sure you let them know that any money put into the bank is to start a savings fund for the baby.
Put a baby picture of mommy and daddy on the table stating, if known, weight, length, date of birth, time, etc. then have each person fill out a "baby prediction". Have them just fill in the blanks of what they think the baby will look like (hair & eye color, length, weight, what date, time, and look like mommy or daddy)
at 2:02 AM on Aug. 15, 2009