Hiya-
Well, as mentioned by the other gentlemen on this thread, you might have quite an interesting time of using this approach for imaging.
The sensors that you have mentioned in your link above all have very large angles of dispersion. That is the beams sent out and the areas received all are pretty broad.
I believe that the range sensors "applications" as mentioned on the link are primarily used for finding walls or obstrctions in the robot's path.
A little googling on robotic's websites at some of the more aclaimed universities (MIT, Cal Tech, Berkley, etc, etc) might show you more on the "state of the art" for image resolution.
Indeed, many of the "robotic cars" put on by DARPA for self navigating vechiles, had actual optical visioning systems (think TV cameras) for their sensing devices. Several were binoccular in nature (just like our eyes measure distance).
Your robot might get a very rough idea about its environment from a scanning ultrasonic rangefinder, but you might have to put in an extraordinary amount of effort to accomplish this.
You might be better off looking at CCD sensors.
Best of luck!
Cheers,
Rich S.