Here's an excerpt, but do read the whole thing. It's fascinating:
"The depth image on the Kinect has a field of view of 57.8°, whereas the Hokuyo lasers have between 240° and 270°, and the Neato XV-11's LIDAR has a full 360° view.
In addition to being able to view more features, the wider field of view also allows the robot to efficiently build a map without holes. A robot with a narrower field of view will constantly need to maneuver to fill in the missing pieces to build a complete map.
One solution would be to add more Kinects to increase the field of view. The main problem is the sheer volume of data. 640 x 480 x 30fps x (3 bytes of color + 2 bytes of Depth) puts us at close to the maximum speed of the USB bus, at least to the point where you are only going to get good performance with one Kinect per bus. My laptop has two USB buses that have accessible ports, and you might get four separate buses on a desktop. Assuming you down sample until it works computationally you still have to deal with power requirements, unless your robot is powered by a reactor, and possible interference from reflections to deal with.
Another simpler approach is to mount the Kinect on a servo to pan horizontally, this however reduces the robot to intermittent motion where it is constantly stopping and scanning. Depending on your robot's mechanical design you may be better off rotating the robot."