just got a laser alignment tool from Northern Tool and Equip. that looks like a good addition to the ShopBot. it's their Torpedo Boy Laser Level w/ tripod for $24.99. it has a magnet mount on it and can be fixed to the Z-axis to provide an offset for the tool's x-y zero. it has a small spot size as well as a line generating lens. you can use the line to set zero as well as align stock.

da