My 3-year old son had a Blue's Clues party outdoors. We played "Pin the Flag on Mailbox."  I enlarged Mailbox from a coloring book picture on an overhead projector, drew and laminated flags for each child, and made blindfolds with material printed with envelopes. We also played "Blue's Clues."  I found Handy Dandy Notebooks at Target.  On the back of each notebook, I placed a sticker.  Then on index cards I drew 3 clues. I placed a matching sticker on the back of each of the three clues.  The clues were hidden all over the yard, and each child had to find the three clues that matched his sticker.  Every child was trying to figure out Blue's favorite animal, but each child had 3 clues to match his notebook. Therefore, each child could find their own clues and solve their own puzzle. Each child got a certificate (taken from a coloring book) for guessing their clues.  I bought red pails and yellow shovels, painted then with a face and each child's name, and let the kids play in the sandbox. They got to take the shovels and pails home.   We had a blue pawprint cake made from one round cake and 4 cupcakes, blue Kool-Aid bursts and Slippery Soap ice cream  made from vanilla ice cream sandwiches with blue frosting dots for eyes, a red hot for a nose, white frosting mouths, marshmallows for bubbles at the bottom, and licorice arms.     Everyone had fun and we got some great pictures.