Possible Duplicate:
What’s the best Remote Desktop Application?
What software/ web service can I use (both free and commercial) to allow people to remote desktop into my computer from anywhere as long as there is internet?
Same thing, but reverse: what software/web service can I use to access other people's computer?
It should work through all the firewall, easy to use, simple to setup, intuitive, etc.
I think for the first case, would be easiest if the software creates a link (sent via email) and the person just clicks, enters some access code, and tada he's connected.
Same with the other case.