Hall affect limit switches

I like this idea, most of the limit switches I use for CNC are mechanical based.  This is a magnetic field based and is contact less.  It doesn’t look like it would cost much to make either..

http://hackaday.com/2013/04/03/hall-effect-limit-switches-for-a-3d-printer/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+hackaday%2FLgoM+%28Hack+a+Day%29