These ebuilds come from http://wnx.wisegears.com/.
If you have some problems, go to the official site first.
nvidia-bl : Support for backlight control of nvidia cards on some laptops ( https://launchpad.net/~mactel-support/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a wnx
For Paludis use this rsync : rsync://gentoo.zugaina.org/wnx-portage
If you have a problem : ycarus(-at-)zugaina.org