While there is a certain irony in chopping down more trees to make treehouses, the fact is that a treehouse would likely conserve more energy and harm the environment far less than the average household. Plus, Swiss Family Robinson is awesome.

WebUrbanist has a post where they have pictures of some of the coolest treehouses around, with such elaborate features as glass roofs, swinging vines, and even one that looks like the treehouse in the Ludacris video for “Saturday (Ooh Ooh).” Judging from these pictures, once you have kids, you may need contractors to compete with the neighbors.