I found two ways of connecting my Mac to my OpenSolaris box remotely:
1. Running a gnome-session over SSH.
$ ssh -X email@example.com gnome-session
And up pops a X11 app on the Mac and you can see the desktop. It’s slow and clunky, but it works.
2. Using Mac Snow Leopard’s built in Screen Sharing client.
This requires more configuration on the OpenSolaris side of this – apparently the Mac OS will only connect to a server that requires authentication in its expected method. This article showed me how to do it: Share your OpenSolaris 2008.11 screen to Mac Os X.
The second method is much prettier, doesn’t have windows that disappear under the Gnome application bar at the top, neatly puts everything in a window to the remote machine, and to boot it is actually way faster too.
Oh, and here’s a trick. Screen Sharing application for some reason doesn’t give you a nice interface to connect to a remote machine manually (as opposed to clicking the Share button in a Finder window). This also works, open your favourite web browser and type vnc://opensolaris.local/ to launch screen sharing on the machine “opensolaris.local” (also works with ip addresses).