Hey Scott. Coop Cooper from Smalltowncritic.com here. Thanks for the great DIY info. I wanted to share my version of the PVC rig for you and your readers...
I built my PVC rig a few months ago and have used it quite often since then, modifying it to meet my preferences and needs. I'm glad to see a lot of your readers find accessories (like the hockey puck fast plate) and create handlebars below the rig as I did for a solid shoulder mount.
From the pictures, you'll notice I added an extra 5 inch section to the rear bar. I use this primarily as a shoulder mount, but kept it just short enough so I can use it like a rifle stock if I need a certain angle or different way to hold it for comfort. I also added several ounces of lead shot padded and glued into the rear and bottom tubes of the stock. This gives it a nice counterweight since the design is fairly front-heavy.
I also off-centered the rear handle and shoulder structure, building an extra bracket/platform so my camera could stay centered on the rig without pushing it all the way up to the front bar. I did this because I wanted to be able to see through the viewfinder and since my DSLR camera is a mirrorless Panasonic GH1, I'm easily able to do this when the rig is mounted on my shoulder. This also puts the flip-out, articulating viewfinder more in-line with my eyes under most shooting conditions.
I also have the 3 handlebars (they look ridiculous but are the best I could find at the time) at the bottom which can act like a stand, but they are also very comfortable to use in a shoulder-mount situation. I highly recommend that for anyone who wants to use the rig mounted this way. The last handle sticking out from the top bar was another helpful choice I made considering it adds balance and stability due to the off-centered rear stock when you're holding the rig low and tilting it upwards.
Booming out front from the top bar 4-way coupler is a homemade shockmount. Seated in the shockmount is a Zoom H1 doubling as a boom mic and is mounted on a mic clip stand adapter I got in the H1 Accessory pack. I had to extend the adapter a couple of inches with a PVC coupler so it would fit. If anyone has tried it, you know that using a Zoom field recorder on a camera or rig without a shockmount is a disaster. It picks up every vibration and movement, and I've found this solution – as ugly as it is – eliminates all of that. The cable connecting the Zoom H1 to the camera is a Sescom attenuator cable (with a Y-splitter for headphone monitoring). This audio setup still creates a lot of in-camera hiss on the GH1 so I recommend hitting the record button on the H1 when filming to pick up an extra, cleaner track.
I painted the rig and unfortunately used Gaffer's tape for the rest which didn't turn out well. Since this configuration has a lot of joints, it creaks like a 110 year-old grandma so epoxying it all together is a must and eliminates 90% of the creak. I left the top bar 4-way coupler and the T-joint coupler the camera rests on unglued so I can adjust their swivel position if need be. With the camera it only weighs about 6 or 7 pounds.
It ain't pretty but I've used it to film a lot of live music acts and one gubernatorial campaign video (here's the link... http://youtu.be/QQWEzgT91Tw The handheld shots are mine on the rig and the camera used was a hefty Canon XH-A1).