I have a particularly ingenious defense to prevent reformatting: I have a 3,1 Macbook Pro with a Superdrive. Not only is it incapable of reading any optical media, but getting your disc back from the furry recesses of its lair is almost impossible.
Ha! I understand entirely. I have the same hardware, and I'm replacing the (now broken) optical drive with an MCE OptiBay and an SSD currently in the mail.
I did the same. Watch out for 1.7 fw upgrade for the sata bus. My mbp couldn't handle the amount of data sent and as a result would crash every time I would install os x. Downgrading the firmware to only allow for 1.5Mbps worked well and it is what I am currently running. Email me if you need a link to the downgrade.
