I loved the candy bars in diapers game we played at my best friends shower...melt candy bars into diapers and then people have to guess what kind it is.
Take a ribbon and have people sign it (depending on the # of people, it may need to go around twice.) Then wrap it around the mom's belly and what ever name is where the string comes together around her belly wins.
Price guessing of baby items (like price is right).
We also addressed envelopes for thank you notes (one was at each place setting...saves the mom to be a lot of time)
As mom-to-be is opening presents, set a timer for random times, when the times goes off, who ever gave the present that the mom-to-be is currently opening gets a prize.
Fill in the blank nursery rhymes.
On a notecard each guest writes a question that new moms would ask or would want to know. Then flip it over and pass it on the person to their right. The person then writes the answer to their question on the back of the card they now have. Go around the room and have people read the front then the back - they will obviously not go together but that is the point...mom-to-be picks her favorite/funniest/weir dest whatever she wants and the person holding that card wins.