I would like to know how far from the wall people are putting their M22's? Mine are about 2 or 3 inches. Before, they were about a foot. The main difference I have noticed is that there is a bit more bass response.

Is their an 'optimal' distance they should be from the wall?

I tried it close to the wall and bass is definitely higher but sound staging is not that good. Having the speakers 2-3 feet away from the wall gives better staging and clarity. You will notice the music coming from the center spot between both of your speakers rather than from each side of the speaker. I have mine at a little less than 2 feet because any closer and it doesn't sound as good. Any farther and I will hit it AGAIN with my computer chair as I did before, giving a nice gash on the inside left speaker as it fell. There is a 1 inch long gash into the veneer of my 3 week old speaker. Right now I have black electrical tape covering the gash like a band-aid.

Patch, the general rule for smoothness of response(bass reinforcement and imaging are separate matters)is to have the speakers positioned so that the distance from the center of the woofer to the floor and two walls is different. One of the distances can be relatively small, say one foot, but the other two then should be possibly three and five feet. These are about the distances I use with my M22s. The idea, again, is not to have the three distances equal, which would reduce the smoothness in the 100-500hz area because of boundary effects.

If you want to hear how good the imaging depth and transparency can be, try pulling them out three feet from the wall, maybe just a hint of toe in depending on the distance to the side walls, plant yourself in the sweetspot and put on some Dianna Krall or Pattie Barber. Neat, eh?
I realize this placement is not practical for most folks' set up but do try it to see what I mean.