Lots of folks having fun with the idea. Guess Real Men don't use mirrors. Count me in the Wuss category, then, because I really want a mirror, just haven't figured out an easy way to do it, yet.
Why do I want a mirror? Simple. I keep backing into things. Some may remember that I forgot a big hole was behind me, backed into it, and turned the tractor upside down with me sitting in 3' of water underneath it...then, there's the pain the neck of turning to see where I'm going when box blading, etc. I've learned to drive trucks, trailers, RVs and such completely with the use of mirrors -- I rarely turn my head to back up -- and I want the same convenience on the tractor. When we were racing, we used a WINK multi-element mirror, and I've been thinking about the same thing for the tractor -- let's you see everything behind you.
So, there's some good ideas above, but without a canopy, I haven't found the right solution, yet. I guess I'm going to have to build a canopy and mount a WINK on the leading edge.