I wrote about connecting to RDP over SSH, but that relied upon PuTTY. As I'm now using OSX, I have access to OpenSSH. This makes things easier.
ssh -L <localport>:<remotehost>:<remoteport> <sshserver>
ssh -L 8001:192.168.0.1:3389 adamkdean.co.uk
Now you can connect to local port 8001 with RDP.