Chocolate Themed Babyshower

If the future mommy is a chocoholic, you could center the Babyshower around a chocolate theme. Get the napkins, tablecloths, balloons, plates, plastic silverware etc. in a chocolate brown color.
Next, get all kinds of baby related items in chocolate, such as toys or rubber duckies to place all around the room and the table. Sprinkle chocolate chips around each place setting for the guests to eat at will.
For dessert get a big chocolate cake decorated for the shower and melt some chocolate in a bowl for dipping fruits.
Make a big gift basket full of chocolate items and other useful gifts for the mom-to-be. You could also include chocolate scented lotions and soaps so she can pamper herself in all chocolateness.
As a detail, you could also place chocolate pacifiers as part of the guests' party favors. All these items can be found at specialty chocolate stores or online by searching on Google or other search engine sites.
When you send out the invitations mention that the shower has a chocolate theme and give the guests an option to bring anything chocolate that they would like. Chocolate related baby items, such as clothing with chocolate themes or colors are also a good idea.
Make the mommy-to be's shower a great event where she can have her fill of a favorite treat and enjoy it to the fullest!