For my son's third birthday, we all decided on a Bob the Builder/Construction party.  We decorated the house in yellow CAUTION tape and hung replica construction signs throughout the house (walls and hanging from the chandelier).  For the "cake", we made chocolate brownies and cut them into small bite size pieces. We purchased an inexpensive big yellow dumptruck and tipped the back down. The brownies were spread around the back of the truck and loaded up inside.  We used construction cone candles to surround the pile.  For snack items, we placed chips and dip and cookies in unused paint trays. When the guests arrived, each child received a handpainted nail apron from the local hardware store.  They were very inexpensive and had the name of the store on them originally.  Some fabric paint covered up the logo and I wrote the child's name over that.  They also received plastic hardhats with their names on the front. On the back, they read, "Can we fix it?" Shortly after the children arrived, they ate a brown bag lunch (just like construction workers) out on the back deck.  The backyard was decorated with caution tape, including our fence.  Each child could get his picture taken while holding a shovel and wearing his/her apron and hat in front of the CAUTION taped fence. For craft time, the kids first made a toilet-paper-roll Bob using a pattern I found on the internet. Then, we had to "build" him a house. I found 12" cardboard houses at an Internet birthday supply store. They popped out the windows and colored the house and roof.  The kids were able to play a game of "Pin the hammer in Bob's hand". I drew a 3 foot picture of Bob the Builder on posterboard paper. To occupy the time of the younger or shy guests, we had wooden blocks and Legos on child-size tables to play with and various construction toy vehicles available. After brownies were eaten and presents were opened, each child took home a brown paper bag filled with Bob the Builder stickers and a coloring puzzle (downloaded from the Internet and backed onto lightweight cardboard)... and their hats, aprons, houses, and Bob puppets.