Try this site out if your looking for pc remote control software that allows you to connect to a remote computer over the internet to provide desktop tech support on demand to. The end-user that's on the computer your looking to control remotely just enters your email address in the righ on the homepage to login. They then click connect and the software downloads to their system with a configuration to connect back to yours. This concept is done I think by alot of companies but they make you have the same configuration for your network. If it changes it's going to cost more money to get it changed by them. This online computer remote control for support site allows you to make changes on the fly. If your configutaion changes you could change your settings through an account profile page. I openned an account an trying it out.
Another product which I've seen in action which is pretty good for colaboration software is made by linktivity. This software package has alot of bells and whistles. The same package does remote support too. You have to but a server fot this software.