Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

I am wondering if there may be some way to use mirrors to view both
sides of a circuit board at the same time as an aid to aligning
circuit traces. I am thinking something like an old stereo photo
viewer. Basically each side of the board shows in each eye and the
second side adjusted until the holes line up.

Alternatively maybe two digital cameras could be used and the images
superimposed on a monitor.

There may be a tool that does something like this, but I could find
nothing on google. I probably was not using the correct terminology.