Try some of these links:
http://www.orientaltrading.com/ui/browse/processRequest.d...
http://www.partywedding.com/themes/viewprod.asp?prodID=4897
http://thepartyworks.com/index.php/cPath/1198_79_535
http://www.tinyprints.com/products/ProductView_894.htm
http://www.marthastewart.com/article/decor-and-favors
Also I found these ideas on line:
Polka Dot Baby Shower:
Make circle-shaped sugar cookies by rolling out cookie dough and cut out using a glass. Frost with assorted pastel frosting.
Cut circles out of colored cardstock and hang from the ceiling with fishing line.
Serve circle-shaped candies in cute bowls. Skittles and M&M's work great!
If the shower is outside, have a buuble machine set up to float bubbles all around
Make sandwiches cut into circles
Tie polka-dot ribbon around vases
Serve food on polka dot plates
Use a melon baller and scoop out assorted melons. Serve in a hollowed-out watermelon
Sprinkle polka-dot confetti on tables and countertops
Make a round cake and frost it pink or blue - sprinkle with polka-dot confetti or pipe on polka-dots with another color