For my daughter Francesca's third birthday I planned an Under the Sea theme party. For invitation we created an enhanced watercolor summer photograph (using adobe photoshop) of my daughter and printed it on card stock. The watery blue vellum overlay attached with an irridescent bow (crafts store) read Under the Sea, Under the Sea, Please Come Celebrate Turning Three with me. Then we said "Catch Us" for the date, "Nautical Time" for the time, " Port" for address, "SOS" for rsvp. We mailed the invitations in a black folded mailer sealed with a bright fish sticker.  Envelopes were addressed with a bright blue gel pen. We decorated our lime green playroom with blue and green x-mas lights (picked up on sale for $1.50), giant paper fish suspended on fishing line from the ceiling, and child-made jellyfish and crabs.  We also bought three dozen balloons in shades of aqua, blue and green.  The bathroom mirror was decorated with lime green rope lights and plush fish on suction cups. We also used a blow up palm tree and pinata to create a festive environment.  Both "Nemo" and "Ariel" made an apprearance (in the way of some decorations), but we kept the Under the Sea theme broad. A last minute addition was a homemade, life sized aquarium made from the box our new excercise machine came in. We painted it with fish and cut portholes and doors. What a hit!! For the party we planned simple, old-fashioned age appropriate activities including a jellyfish craft and frosted/candy decorated fish-shaped sugar cookies. These were both really big hits. We bought a disney under the sea CD and did the limbo (with a wrapping paper tube covered in streamers w/ tails), played pin the tail on mermaid (made with online clip art and blown up to 20" x 30"), did an under the sea version of the hokey pokey and had a great fish pinata.  Lunch was served in our dining room (one table for adults and a little table for the kid's)- we kept it simple and crowd pleasing with a menu of goldfish, pizza and lemonade (with dolphin ice cubes). Tables were set with shades of paper products in aqua, blue and green.  Inexpensive flowers were purchsed at Costco and fun blue/green arrangements were at the center of each table. The kid's place settings had a sea creature party blow out, party hat and leis.  The cake was a labor of love and inspired by the multi-tiered cake on the Jan 2004 issue of Gourmet magazine.  A layer cake frosted in buttercream with sea colored bubbles.  Then three layers of frosted cupcakes in various shades. Served with vanilla ice cream, it was a big hit. Before the kid's left they were given personalized (created using various clip art and fun fonts) sheer blue organza party bags (on sale at Kate's Paperie) filled with fish clappers, a set of sea creatures, blue bubbles, fish slinkys (Oriental Trading)and swedish fish.    The party was so much fun.  My daughter and her friendes seemed to loved it.