Bob the Builder-4yrold. I kept decorations limited to orange, yellow and bright blue. As each guest arrived, he was given a Home Depot toolbelt and plastic hardhat with his name on it. We have a huge sandbox that we filled with dollar store construction trucks-the kids could play there anytime during the party and keep a toy. There were two tables set up for each child to make party favors as they arrived. I saved small empty water bottles and wrote each child's name in bubble letters, placed colored sand in bowls and then let them fill their bottle with a spoon and funnel-virtually no mess!  The other table contained gift bags in assorted colors with Bob the Builder coloring pages glued on each bag-the children chose the bag they wanted and colored the picture and wrote their name.  After the bottles and bags activities, they had wheelbarrow races to construct a wall.  I found the wheelbarrows at a dollar store, and had purchased cardboard bricks through Lillian Vernon. After the wall was built, they put the bricks back in a container by carrying them through a playtunnel maze-they loved it! Next, we played red-light/greenlight-huge hit! They then went to the piñata and filled their colored bags with the candy. I filled it with assorted items from the dollar store. The kids especially loved paint brush lollipops I found at Wal-Mart-they thought that was the coolest!  After that, it was cake and goodie boxes. For food, I had filled a clean dump truck with apples and oranges, clean sand pails with beverages, and I used clean colored paint trays for veggies with dip in the "trough" part of the tray-the moms loved that! Everyone was having such a great time that the party lasted 3 hours (it was only supposed to last 2)! The kids enjoyed playing on a jungle gym set and in the sandbox. Us moms actually got to chat without interruption! This was a relatively low cost party because I kept the "theme" part limited to colors and related items.