Hi, 
Thanks for the awesome post. I had some issues using ubuntu 12.04 LTS and GTX 580. I run into issues with the initial diagnostics. Namely, "$env DISPLAY=:0 glewinfo | less" reports: 
No protocol specified
No protocol specified
Error: glewCreateContext failed

The xorg log does not show any errors  and  "$/usr/bin/X :0 &amp;" tells me that X is already running. 

Any ideas on how to troubleshoot some more? 
Thanks in advance.