> It is probably the best 2"x2" glass signal mirror on the market.
Thinking about that, while AFAIK, it is not currently on the market, this is the fanciest 2"x2" glass signal mirror I have seen:
[img:left]
http://www.flickr.com/photos/signalmirror/8222358593/[/img]
Complete with peep + crosshairs sight, signal shutter, tripod mount, and gimballed 2nd mirror in case the sun is opposite the target, this is hands down the 2"x2" mirror I'd want for signaling to a fixed target.
A bit bulky with all that metal hardware though.
Go here:
Portuguese Heliograph Type 938C Right Side Isometric 1 to read about it (and there are "mouseover" annotations).