Interesting, I was trying to do this very same thing yesterday. And failing, I might add. I was using the Remote assistance built into Windows Live Messenger, and I suspect the reason it didn't work is that the person I was connecting to was probably behind a University Firewall (I've had it working in the past). It's worth a try if you both have MSN though, means you don't have to install anything else. Start a conversation with them, then 'Actions' tab and 'Offer Remote Assistance'.