How do I use VNC to "share" :0? What I would like to do is be able to remotely access the screen visible on the server computer, but right now I can only access :1 (or any other desktop started with the vncserver command).

Hope my wording is understandable. Thanks.

eh sorry forgot to RTFM...

from the FAQ (http://www.uk.research.att.com/vnc/faq.html#q22):

Q22 Can I remote the normal X display of my workstation (display :0) in the same way as the Windows server does?

It is possible to add VNC support to a standard X server, but we have no plans to do so at the moment. We've been told that Jens Wagner has done this - see x0rfbserver. We tend to run all our X sessions as VNC sessions and only use the local X server to run the viewer. It's very fast when on the same machine as the server! If you feel that it's overkill to run two X servers on the same machine, you might consider Ganesh Varadarajan's svgalib- based viewer.