plot 3d points on a 2d plane

Want to plot 3d points on the screen? this code will enable you to do this! I did not write the original code that calculates the x,y co'ord from x,y,z co'ordinates, but I compiled it into an easy to use (cut 'n paste) form and added a few examples of what you can do. lines wouldn't be a problem either, just write a wrapper function to do the job! Please vote! (I didn't do the trig, but hey, it's just math ;-) and I did the rest!)