If you were really desperate you could try using "Back orifice 2000" which has keylogging capabilites, realtime view of their desktop, hijack mouse and keyboard, view and kill processes and basically anything you can do from their computer and more. if if you are worried about security in that you can download 256bit encryption plugins and Stealthy TCPIO protocols and other such things f the like.

-- Dont flame me for suggesting a "trojan" as i said "If you were really desperate you could try..."