You can bypass the setup wizard altogether by tricking osx into thinking it has already run.
Reboot, hit F8, and enter -s
After pressing enter, you'll eventually end up at a command line.
/sbin/fsck -fy /sbin/mount -uw / touch /var/db/.AppleSetupDone passwd root...and enter a new password.
This will at least get you into osx, though you'll be running as the "root" administrator account... which is always recommended you don't use. (I believe you can use the "adduser" command if you'd like to setup a proper account)
You also will have skipped all of the configuration, so you'll be forced to use US English on a QWERTY keyboard, you will not be able to migrate your old account off another mac, you may not be able to setup networking manually.... But at least you'll be able to log in!