Let this thread be a place with links to all of the various companies / people who make pinhole cameras for sale....
I'll start off with some of the obvious, well known makers/sellers.
Zero Image: http://www.zeroimage.com/
Lensless Camera Company: http://www.pinholecamera.com/
Walker Cameras: http://www.walkercameras.com/
I hope you all join in with links to your favorite makers and sellers.