I think the first thing to try in order to get to the CLI and a working desktop is to load the Ubuntu recovery entry on Grub. This should be the entry directly underneath your normal boot option and look something like this:
Assuming this loads and you get to the login screen, then you need to click the user you want to load up (DON'T enter a password yet). From here on the subsequent screen there should be a button at the bottom labelled 'sessions'. Click this and select the 'failsafe' option (I believe this is what it's called). Now enter your password and you will be taken to a CLI.
Ubuntu, with Linux 2.6.35-25-generic (recovery mode)
I think this is worth a try, but not 100% sure it'll work.
EDIT: Looking at pqwoerituytrueiwoq's entry above, my advice may not be necessarily - I was making the broad assumption that the Ubuntu Recovery mode acted in the same way as the OpenSuSe failsafe mode!