Just thought I'd update my touch-off plate story. With the help of "erniebro", Lester Caine of the yahoo forums and the Mach 3 Forum, I was able to get it all worked out. This thing is going to be such a huge time saver as it works perfectly and accurately to within .0002 tenths. Just unreal.
My setup is a Microproto DSLS 3000 and unfortunately there were no extra inputs for a probe so I had to use the 4th axis input (which I'm not using at the moment) to make this possible. I "snuck into the controller plug and just connected my plate connection to pin 15 of the printer port and had to enable the probe in ports and pins and disable the A++ limit input. Then I just grounded it to the machine and it was ready to go. When I'm ready to do a 4th axis, I'll add another parallel port.
With erniebros' vb script, ( thread can be found here: http://cnczone.com/forums/showthread.php?t=56079 )I can find the centers of cylindrical parts, edges, and surfaces. For now I have just the touch off plate made which is just some PC Board material (.062), but I will soon make the edge plates and cylindrical fixtures for finding centers.
Some pics for you: