It seems that the SD card slot in the new MacBook Pros does count as a bootable device; all you have to do is install OS X onto a card, set it as the default boot device, and you’re good to go. Why would you want to do this ridiculous thing? The idea is you could boot from it to address emergent hard drive failure, data corruption, or viral attack. Just kidding about that last one.
I don’t know, though. In my experience, Macs generally only fail suddenly and cataclysmically, as in the case of my brother’s MacBook, which shut down in the middle of playing a song, and never woke back up again. You never have a chance to preempt problems because OS X is so good at hiding them.
Can I install Mac OS X on an SD storage device and use it as a startup volume?
Yes. Change the default partition table to GUID using Disk Utility, and format the card to use the Mac OS Extended file format to do so.
I’m hoping they add a startup key — like holding the mouse button on startup to eject a stuck CD — for booting from the SD. It makes a lot more sense that way.
[via Apple Insider]