I just built a bootable NetBSD/i386 1.3.2 installation CD and was
pleasantly surprised by how easy it was.  The boot.fs file from the
NetBSD distribution can be used as the boot floppy image on a CD with
an El Torito style boot catalog, without any changes whatsoever.
Here's the procedure I used, in the hope that it will be useful to
someone else.

  1. Create a new directory and cd to it.  Put a copy of 
     the NetBSD-1.3.2 directory from ftp.netbsd.org 
     (or a suitable subset thereof) in a subdirectory
     "NetBSD-1.3.2".  You can also add other subdirectories with
     other useful stuff you may want to include on the CD. 

  2. mkisofs -R -o /tmp/cdimage \
       -b NetBSD-1.3.2/i386/installation/floppy/boot.fs .

  3. Burn /tmp/cdimage on a CD-R using cdrecord.

The resulting CD is bootable by most PCs with a recent BIOS and an
ATAPI CD drive.  It will boot into sysinst just like the install
floppy, and you will be able to do an "install from CD" using the
default distribution file path.
-- 
Andreas Gustafsson, gson@araneus.fi