If your going to read one, start with this thread...It was the original thread I started with a year ago, some of the changes are noted by Mississippiman himself. Most people are mixing the SM in with the mud in varying %, depending on the projector your going to use and your room conditions...

good luck

http://www.avsforum.com/avs-vb/showthread.php?t=359152&highlight=mississippimud

I'm also in the market for a new projector. I went to B&H to see the 900 right next to the Z4, but it wasn't a fair comparison b/c the screens were different. I'm pretty set on the Z4 and a DIY screen. I have about 35 sheets of 1/2" birch plywood....can I use this or should I pick up a sheet of MDF, Gatorboard, etc?

If you don't want to mess with the paint methods, there are lots of other options. Depending on how big of screen you want, you could go with Parkland Durotherm Lite panels. They are a corrugated PVC material that is 4' x 8' x 5/16" thick. One side is smooth/flat/matte white and works great for a screen. Many on AVS use this method and trim or incorporate a masking border to get the desired size. It can be found at Menards in the paneling aisle, or may be available at Lowes or Home Depot. There are other options like Black Out cloth that can be found at JoAnn's Fabrics, or just Ultra Pure White Flat exterior paint works good as well, on un textured walls...