Location: Phoenix, AZ
As coincidence would have it, this is the house located immediately next door to the house in the photo posted previously, except it was photographed on a different night.
The blurry tree branches are the result of the wind gusting during the long exposure. Although this effect wasn't obvious at the time, I find it interesting to note afterward that only the outermost parts of the tree have moved and not all of it. I've also noticed instances where the upper branches of a tree can be rustling, yet I feel no air moving across my face at ground level (well, six feet above ground level.)
A larger, higher resolution version of this photo can be seen here: http://www.canyonero.com/files/1524099958.jpg