I use devilspie to arrange the windows of monitoring tools (htop,ifop,iotop,nethogs, bmon) at the third workspace.
In case I need the details about some process activity, I switch to the third workspace and watch all I need immediately. It is very handful to me. But these tools consume resources of my week ATOM box which I want to be free when I don't use the third desktop.
That is why I'm looking for a way to stop (kill -STOP) these monitoring processes when I move from the third desktop and coninue them (kill -CONT) when I come back. I figure out there might be a kind of hooks in DE which trigger when desktops switch.
I use LXDE in Lucid. Any Ideas?