Digip, I see where you are coming from. However, we work in an open plan office, so anything that can be seen with a screenshot, can also be seen by simply walking past him..
We have policy in place which states that if programmers are installing software that is not linked to Development (Our company designs software) then they must ask IT, aka, me and my boss.
Also, I have also used LanSweeper to create a list of installed software and sent that to my manager to check what is and isn't allowed to be installed.
Hope this is of some help.
TuX^