Having wire gauge sizes as a unit of measurement would be useful in some situations. Mainly for hole and cylinder size, like for easier modeling wires, or holes for wires in circuit boards or other applications and for use as drill sizes for tools. Granted, it is not that difficult or time consuming to look up a conversion chart online somewhere, but it doesn't seem like a particularly difficult addition. Also, having number/letter drill bit sizes pre-programmed could also be useful in similar situations. At the very least these would convenient in the Create Hole and Sketch Circle tools, but it would also be great if the measure tool could note when a hole or cylinder's diameter is equivalent to one of these sizes and if they could be used as measurement in drawings.
There's probably also a few other specialty units of measurement that would be useful in specific circumstances. Just thinking about it as I type, sheet metal gauge sizes could be useful in some tools as well and I'm sure there's many more.
