See Vine Server for a possible solution.
Another free possibility, from Use multiple simulataneous GUI accounts :
Here's how to have two GUI users
active at one time on the same
machine. This hint is a summary of
this hint on the macosx.com
forums; read the original post for
much more detail.
Here are the basic requirements:
- Vine Viewer
- Mac OS X 10.4
- Multiple user accounts on the system
After you have two or more accounts
set up on one Mac, install Vine Viewer and
start the server. Once started, Fast
User Switch to the other user on the
machine.
Now from another computer, use a VNC
viewer like Chicken of the VNC and
point it to the Mac. Even though the
Mac is logged in as another user, your
VNC session goes to the original
account, allowing both of you to use
the machine at the same time.
