[Soundy]

VNC is great, but a bit to set up. I use UltraVNC, which has a "mirror driver" that makes video a lot smoother.

For something simpler, you can use TeamViewer, which I believe is based on VNC at its core. You install the full version on all your PCs, and then any of them can remote to the others, without need for port forwarding. You can create an account and add your computers to it so they're readily available from a list instead of having to remember IPs or system IDs. And you can login to the TeamViewer website and access them from there. They have iOS, Android, and I think Blackberry apps for remote control - just add your login, and all your machines are there. Best of all, there's no monthly charge - it's "free for personal/non-commercial" use (licensed version is a one-time charge). They also include a "monitor driver" that greatly improves video speed... and yes, you can do video and sound through it, although the quality can vary depending on your internet speed.