I have been building Squeeze+Trinity live cd's for some time. I use my
own scripts mainly as I found official Debian-Live quite difficult to
get exactly what I wanted.
Remastersys is really good. I use it sometimes. It is designed for
stable; a squeeze version is available but you will need to modify the
current version.
You need installed live-initramfs 1.177-1 (get from
snapshots.debian.org) and grub-legacy.
http://www.remastersys.com/forums/index.php?PHPSESSID=3sugievt9bg9or5p0nhlb…
is worth reading.
In addition you need to hack the script live-initramfs script
"15autologin" (I posted details on the above link) and
remastersys-installer.for Trinity to work properly
If there is any interest I could post here more details. My Live ISO
(700mb) is available on request, would appreciate some testers!.