One fairly nice way to get a remote gnome session with a minimum of fuss is to use Xnest. This just makes a little X server in a window.
Firstly, setup xauth to allow you through
ianw@lime:~$ echo $DISPLAY :0.0 ianw@lime:~$ xauth list localhost.localdomain:0 MIT-MAGIC-COOKIE-1 bd72c2....6c8ab8 lime/unix:0 MIT-MAGIC-COOKIE-1 9a5c6...648d4bffd localhost.localdomain/unix:0 MIT-MAGIC-COOKIE-1 9a5c6b555f...bffd
Copy the cookie that corresponds to your current display to a new one for display :1
ianw@lime:~$ xauth add :1 MIT-MAGIC-COOKIE-1 bd72c2....6c8ab8
Then startup Xnest on display :1
ianw@lime:~$ Xnest -auth .Xauthority :1 &
Then fire up an xterm that ssh's to the remote box and starts up something like gnome-session
ianw@lime:~$ xterm -display :1 -e ssh tutti gnome-session
and hopefully it will look something like this!