* Aug 30, 2012: some updates...
I've been a TightVNC fan for a good while now, and have been an avid user of the independent IPv6 TightVNC client for several years now (unfortunately the author's page went offline this year). I also have begun deploying Windows 7 at the company I work for, and RDP is not always at my disposal: I had to figure out how to get VNC working right, and on IPv6 as well.
This will get VNC working on 7...
1. Daniel Petri posted some nice instructions for getting TightVNC to work on Vista. Since I'm using the IPv6 viewer, I didn't need to install the viewer that comes with the download: just the server and docs.
2. Optional: install the mirror driver (TightVNC 2.5.x re-added support).
3. I added the TightVNC server to the "All Users" Startup folder: it can't run as a service on Vista/7 yet (1.4 is supposed to be able).
4. I allowed Windows Firewall to permit the TightVNC server on public & private networks. I also used the advanced settings to permit port 5900 on IPv4 & IPv6: you may or may not need to go this far.
5. In the Properties for the TightVNC server, I: turned off file transfers;
6. I rebooted and verified it worked. You may need to disable any "basic mode" notifications for when the display changes during remote control.
This will get VNC working over IPv6...
* You can also use my IPv6 toolkit for this!
1. Download the latest stone repeater (I used the XP version).
2. Copy the files in the ZIP folder to a new folder on your system, such as C:\stone
3. Create a text file in the new folder called stone.ini (you may need to disable file-extension hiding in Folder Options). Add "localhost:5900 5900/v6 --" to it.
4. Run a command prompt as Administrator and go to the stone folder. Run the command "stone -C C:\stone\stone.ini -M install vncproxy" (change if you used a different folder).
5. Right-click Computer and left-click Manage. Use the Service Manager to set the "stone vncproxy" service to "Automatic" and start it.
I should also note that the GNOME-based VNC client for Ubuntu Hardy and newer work with this. The Windows IPv6 VNC viewer is also compatible with their VNC servers & shared desktop modes.