It's something that's just been kept present in all the new versions of Autocad, I don't know the original version it appeared, at least R12. It only works once you start a command, and it allows you to move about the workspace as if you were drawing lines (including using object snaps.) I find this is much easier to work with than standard Object Snap Tracking, which interferes too often when you don't need it and turning it on and off all the time is a hassle. I finally stopped turning Ortho on and off all the time by using Polar at 90 degree increments, and only very rarely do I need to turn it off. No more constant reaching for the function keys! :) (Well, there is regular snaps, but I think I will give clicking it off a go, along with polar.) So, if you know about it, do you use it? If you don't, give it a try and let me know your opinions.