by tedm » Sun Mar 17, 2013 8:03 pm
If you follow the directions on this site, first you will need an card > 8GB, it should load only on the card, and each time you want to access it, just boot (in dev mode) and hit ctrl U. Ctrl D on boot, or just waiting 30 seconds will put you into standard ChromeOS (without OS verification).
The first time you go from standard ChromeOS into developer mode, you will wipe out any user data on the internal drive, this only happens the first time you go into dev mode, (unless you subsequently revert to normal mode, then go back to dev mode, again, it will wipe your internal drive of user data, and present an Out of Box system.
I have not yet installed arch on my samsung, I have ubuntu via crouton where I can toggle back and forth between ChromeOS and Ubuntu with keystrokes, but do look forward to trying out arm on the chromebook when I get a 16GB SD card later in the week.