The ones I have seen of family and friends are where the roll of toilet paper or ribbon is unrolled to a guess amount of the mom's tummy at it's widest. Baby food taste test. BAby bingo. Depending on how many are going to be there. Since it's going to be at a small restaurant note that on the invites the importance of an RSVP. Couple friends had a formula taste test also. That could be kind of a long game though.