maybe now is a good time to talk about SCALES.....
I use two scales in my shop.
http://www.rightonscales.com/web/i500.htm
http://www.rightonscales.com/web/kd-7000.htm
these scales are affordable, replaceable (if dropped off the shop table) and work well. As Mike says scales are your best tool in the shop. Scales keep it real.....