Once I had my Epson Powerlite S1 and screen, the next problem was mounting the projector to the wall.  My big problem was that the Epson has a fixed lens with only electronic keystone correction, so I needed to be able to carefully adjust the distance of the projector from the screen as well as the height from the ground.  As little as an inch can make the difference between a square image that fills the screen, and ugly white borders.  I had done the math carefully for a fixed distance mount, but I just wasn't sure I could get it exact enough to satisfy myself, I wanted some flexibility.

Most of the mounts I found were fixed to one spot, typically hanging from the ceiling, and only allowed you to adjust the direction/angle the projector pointed and maybe the height.  Fortunately a friend of mine runs this company that makes mounting equipment for the wheelchair industry and they were able to help me out with this: 

For a couple hundred dollars, I have a mount that can move up/down, left/right on the wall mounts, in/out through the telescope in the middle (tilt there too,) and I get fine adjustments in the 0-180 degree joiner at the projector end.  The whole mount holds together with allan screws, is made of steel and aluminum, and gives me the confidence to hang the projector above my head.  And it looks nice enough for my wife.

Putting the projector onto the mount was a simple matter of drilling a couple of holes through the provided aluminum mounting plate to match the screw holes on my projector and then putting some M4 metric screws in.  I put some high density foam between the projector and the plate around each screw to act as springs so that I could use the screws for very fine adjustment.

The two black wall plates come into two pieces when you remove the two allan screws, and inside there is a hollow and two holes where you can put one or two screws into the wall.  One recommendation I would give is to use a butterfly anchor for the top wall mount.  I tried the push-in kind first, and it pulled right out of the wall when I tested the arm for strength.  Once the allan screws are in place in the wall plates, the main arm won't budge an inch.

Once I had it all mounted, I was able to adjust the distance and aim to get an image that perfectly fit my screen.

TIP: My only mistake in all my math was that I aligned everything to the centre of the projector, not the centre of the lens, so my image has a very slight keystone to it, however no one would notice but me.