These ebuilds come from https://git.overlays.gentoo.org/gitweb/?p=proj/cell.git;a=summary.
If you have some problems, go to the official site first.
petitboot-bin : PS3 alternative bootloader ( http://ozlabs.org/~jk/projects/petitboot/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a cell
For Paludis use this rsync : rsync://gentoo.zugaina.org/cell-portage
If you have a problem : ycarus(-at-)zugaina.org