What about using some of that H-beam stuff that Grumpy Mike mentioned in the "Securing your Pi in a Case" thread. It may not work perfectly on both sides though. ...or a few small studs to lift the Pi slightly off of the slab and then a couple of holes drilled in the side of the slab for the straps ...

I saw your cases and like them as well. It's actually one of the best designs I've seen because the board is actually mounted instead of loose. I think a weighted add-on to your case or a simple stand would be nice. The stand could just be a heavy slab with "grooves" to slide the Pi into. Those "rub...

I just got tired of it sliding all over the place when I moved a cable and I certainly didn't want to put it in an enclosure. The one downside to the Pi's small form factor is that it's as light as a feather.

I started out on a Commodore in the early 80's when I was 6.

...for stability (and price.)

HTC power supplies need to be removed from the wiki list of "good" power supplies. I have tested 4 or more different ones and they are not sufficient. With no devices plugged in they put out 4.71-4.76 v. Under load and with Ethernet and USB devices the Pi frequently becomes unstable.

Please test your power supply using this method: http://elinux.org/R-Pi_Troubleshooting#Troubleshooting_power_problems I'm using an HTC charger rated at 5v/1000mA and with Ethernet, KB, and mouse it's really only 4.74-4.76/700-800mA. When I plug in a USB hub (powered or not) it becomes very unstable...