First off....I have a page on my website that has some unique/sentimental activities for the shower. These are activities that HAVE NOT been done a gazillion times before.
Now....on to the THEMES!!
Bathtime Showers and Sleepytime Hours
(Moons and stars and rubber ducks would predominate. This themed shower would feature a registry with these items::::bath products, hooded towels, pajamas, nightlights, storybooks, relaxing cds, blankets, crib sheets....etc.)
Activities: Onesie decorating. One-handed crib sheet changing contest (timed)----if a crib is readily available!!
Children's Storybook Shower: Classic Children's storybooks like "good night moon", "runaway bunny", "where the wild things are", "i love you this much", "dr. seuss", "but not the hippopotamus", "winnie the pooh", etc. You could ask each guest to bring a copy of THEIR favorite storybook to the shower to start off baby's library. The decorations could be prints from the books, themselves....if you look around you could probably find invites that have these types of themes to them!!
Family Tree: If it is a predominately family-oriented shower....focus on the family tree of the new baby!! Have a family tree made for the new baby and this could be a focal point of the decorations. What a great piece to hang in the nursery, too!! Decorations could be this family tree, and napkins/plates with words like "family", "love", "cherish", etc.
Poker-themed baby shower (a totally different idea that might work really well for the daddy-to-be and his cronies....could occur the same day as mommy's shower!!). Buy in for this poker tourney would be a package of diapers. Winner gets a really great gift certificate to some manly place like Home Depot or Best Buy!!! Decorations could be playing cards with daddy being the "King", mommy being the "Queen" and the new baby being the "Jack"????