Display:
ah sorry that is safe more:

Restart your Mac while holding the Option key on your keyboard until boot options are displayed.

by PeWi on Mon Sep 6th, 2010 at 02:57:00 PM EST
[ Parent ]
Interestingly on this site:
http://support.apple.com/kb/HT1343
the command option is not listed, but you can try

press holding X during startup, as it apparently
"Force Mac OS X startup (if non-Mac OS X startup volumes are present)"

by PeWi on Mon Sep 6th, 2010 at 06:09:54 PM EST
[ Parent ]

Display:
Login
. Make a new account
. Reset password
Occasional Series