Backburner scripts or plug-in

Good afternoon (or evening as the case may be)!

We have been in the process of fine-tuning our backburner set up and are 
hoping that someone in this group can help us with the next challenge. We have 
a large number of PC's (300+) at our disposal in the off ours that we want 
to include in the farm. The challenge is that user activity varies wildly! 
We are hoping to find an add-on to backburner that will detect user 
activity on the individual server node and disable (or enable) based on
activity. 
Does anyone know of a tool that will do this?

Thanks!

Tom

You can try get server running by windows' schedule function. In the setting 
up of the schedule, you can select "run the server when pc is in
idle". In 
this case, server will start up server when the pc is in idle mode.

Nelson