I've already opened the kimono a bit and hinted that I work for Sun Microsystems. Specifically, I work in a group doing bringup and certification work for the AMD Opteron based enterprise and blade servers. My specific task is ensuring VMware's ESX Server virtualization software works perfectly on Sun's x86 hardware. That means I spend much of my day looking at block diagrams, talking to hardware designers inside of Sun, reading datasheets from chip vendors, and looking at thousands of lines of operating system source code.
ESX Server is a product that enables machine virtualization so that typical operating systems such as Windows, Linux, and Solaris all run simultaneoulsy on the same host, with ESX managing the physical hardware resources. What this means is you can do cool stuff like this.