Hmm, I remember reading something about this in the TightVNC documentation I have bookmarked. I'll point you to the website:
Personally I do it through cygwin on my computer. I use the following lines in my cygwin xterm.
ssh -CL 5902:localhost:5901 <mylinuxbox>
Then at my bash prompt I start the vncserver (figure it's safer to only run this when I actually use it). I open the TightVNC viewer connecting to.
Bam, I'm tunneling through ssh. I finish playing in my xfce environment, and then shutdown the vncserver, and close the ssh connection.
I hope this helps.