I'd like to run Folding@home client on my Ubuntu 8.10 box only when it's idle because of the program's heavy RAM consumption.
By "idle" I mean the state when there's no user activity (keyboard, mouse, etc). It's OK for other (probably heavy) processes to run at that time since F@H has the lowest CPU priority. The point is just to improve user experience and to do heavy work when nobody is using the machine.
How to accomplish this?
When the machine in question is a desktop, you could hook a start/stop script into the screensaver so that the process is stopped when the screensaver is inactive and vice versa.