It's Halloween time again, the day when dressing up in silly costumes is required of every conscionable person. Some opt for the scary ghost or the sexy nurse, but others, more thoughtful others, make more of this opportunity. Others like you, my clearly intelligent and attractive reader, who use this opportunity to spread a message with their costumes. Costumes that make an impact. Costumes that enlighten. Costumes that are, uh, related to urban planning concepts. What better way to celebrate this annual day of costuming than with an outfit that tells the world that you are interested in urban planning? Obviously there could be no better way. And so, it is with only a small amount of shame and embarrassment that I present this third edition list of Halloween costume ideas for urban planners.