Tell the guests they can make a wish and drop a coin in. At some point in the shower have them guess how much is in the bank. The one that guess the closes with out going over wins a small prize. -(maybe a little change purse) Then mother-to-be gets the baby bank with all the stuffings.
I am going to do this for a shower this weekend. If anyone writes a poem that will go with this let me know. I think it will be a cute game.

