SirPrimalform: Naturally, I was taking that as a given.
Ok then, if the OP really is so determined not to see the horrendous "black borders", even if it means buying two sets of canvas of different aspect ratios and redirecting the projector based on what he is going to watch/play. :D
I'd probably just live with the black borders if I see something with the 4:3 aspect ratio (watching it on a 16:9 canvas, or a big borderless white wall), just like I do today. To each his own, there are more fish in the sea, do unto others etc.
That reminds me how in movie theaters they sometimes keep moving the curtains on the sides, depending whether they are showing some advertisement in a narrower aspect ratio, or the actual movie in an ultra-widescreen ratio. I always felt that is pretty silly, they could just as well move the curtains away all the way even if advertisements don't fill the whole canvas, but I didn't realize other cinema goers might find it far too distracting to see the "borders" on the sides (because the canvas is too wide).
Hmmm, that gives me a business idea: small curtains that you can slide on the sides of your widescreen monitor, so that you can't see the terrifying black borders on the sides when playing 4:3 games...