http://www.sphere.bc.ca/test/sruniverse.html So I am thinking of making the leap here (these are pretty expensive for my budget). I have never used one before, however, I usually like to write out equations and make little sketches for my personal visualizations. I was thinking a more visual mathematical interface such as the slide rule might actually be beneficial for me. I will be entering my freshman year in a few short months (), and will be doubling up on mathematics courses relevant to a physics degree. So what do you think grey beards? Would it be worth my time/effort? Any suggestions on model's would be greatly appreciated as well!