Hi, my Macs, my PCs and my Linux boxes can all VNC each on my LAN. I would like to try out to VNC to my friend's machines via the internet. I read some articules on the net on how to set it up without success because the terminologies such tunneling, by pass the router etc. confused the hack of me.

I guess I don't really understand how it works. Would someone be so kind to explian to me and give me a step by step on setting it up? For starter, I just want to be able to VNC her Mac, once it's set up, I guess I will have a better understanding and can probably figure out the rest.
Perhaps, some info might help:
On my LAN, my router is the gateway and so is my friend's. We both use Comcast Cable connection. On both ends we have OSX, Windows 2000 pro and XP pro, two distros of Linux- Ubuntu and Fadora.
Thanks a lot.
MacPC.