We are developing middleware, Virtuoso, for virtual machine grid computing that for a user very closely emulates the existing process of buying, configuring, and using an Intel-based computer, a process with which many users and certainly all system administrators are familiar with.
In our model, the user visits a web site, much like the web site of Dell or IBM or any other company that sells Intel-based computers. The site allows him to specify the hardware and software configuration of a computer and its performance requirements, and then order one or more of them. The user receives a reference to the virtual machine which he can then use to start, stop, reset, and clone the machine. The system presents the illusion that the virtual machine is right next to the user. The console display is sent back to the user's machine, the CD-ROM is proxied to the user's machine's CD-ROM, and the virtual machine appears to be plugged into the network side-by-side with the user's machine. The user can then install additional software, including operating systems. The system is permitted to move the virtual machine from site to site to optimize its performance or cost, but must preserve the illusion.
We use VMWare GSX Server  running on Linux as our virtual machine monitor. Although GSX provides a fast remote console, we use VNC  in order to remain independent of the underlying virtual machine monitor. We proxy CD-ROM devices using Linux's extended network block device, or by using CD image files. Network proxying is done using VNET, as described in the next section.