I do a daily manual TM backup at home when my MacBook is connected via ethernet to my 2TB TM. Today I foolishly erased my entire user directory trying to free up space by deleting old unused items. Since my last TM backup was mere minutes before this event, I booted from my USB stick containing the 10.8 ML installer and restored from the TM backup. Over ethernet it only took about an hour and a half to restore the 165 GB on my MacBook's SSD. Lesson Learned: If you're going to screw around in Terminal make sure you have a working backup!