OK, I'll jump in too. I made my mask last night. I used a scaled version of Adam's graphic (thanks again Adam!). I scaled it up to a 9" diameter which resulted in 6mm openings. I went the for sale sign route since I happened to see them while I was at Home Depot getting something else ($1.40 for materials isn't bad). I actually like the material, although it does result in a funny looking mask on one side. The plastic is not too tough to cut and it has a decent amount of rigidity once mounted. I squared it off instead of cutting out the circle and super glued it to a cross stitch circle that I have previously used for my hartman mask.

And the results? It works pretty well! I could clearly see the middle diffraction spike moving to the center between the outer diffraction spikes. I was unable to resolve the 6 small circles when in focus like Dennis' original pictures. So a great improvement over my old hartman mask, but the focusing tool in the latest Meade Envisage seems to let me be a little more precise.

Here's my lovely work of art: