I'm exactly 4.562 feet from the wall

Want a cheap webcam based laser range finder?  Todd Danko did and build two different applications to do it.  One is in Visual Basic 6 and the other is in Visual C++.  Todd based his application off the UB Robotics project.  Using some of the examples from Coding 4 Fun, I bet a .Net port shouldn't be too hard.  Hackaday mentions a an alternative to the video OCX plugin also.  Seattle Robotic Society also has a nice variation of this. 

Throw a few these on and get a DARPA Urban driving contender.

Via Hackaday