Currently Being ModeratedJan 16, 2013 11:17 AM (in response to Julie G.)
Welcome to the brave new world. A parting "gift" from Steve, who loathed optical media in the last part of his life.
There are two choices. The official one is to concoct a bootable recovery partition on a USB stick. Essentially, you transfer what the drive already has for recovery purposes onto separate media in case the hard drive bites the dust completely: http://support.apple.com/kb/HT4848
But we devious Mac hackers went one better. Why settle for a piddly recovery disk that does not have a full system installer when you can have it all? So we go thru the motions of "installing" ML afresh, for which you wheedle the full installer from Apple. But then we use that to create a USB stick that has the whole cat in it and does not need to go thru the painfully slow download again. Details here: http://www.macworld.com/article/1165337/create_a_bootable_lion_install_drive_for _newer_macs.html and to simplify the creation of the stick itself, there's LionDiskMaker (that also works with the mountain cat): http://liondiskmaker.com