Sorry for the recent noise.
For who interested I collect all the info of my one day approach to a safe launch of OpenBSD on the Mac (NB: mine is from early 2011) in a post on http://bsdload.com. Don't missunderstand what I wrote, starting an OpenBSD live installation with an existing MacOS installation to mantain and without EFI is not that easy. So, the precaution to backup your data before to start is always a valid suggestion. -Dan
