libappindicator : A library to allow applications to export a menu into the Unity Menu bar ( https://launchpad.net/libappindicator )
nettle-compat : Low-level cryptographic library (6.2 ABI) ( http://www.lysator.liu.se/~nisse/nettle/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a steam-overlay
For Paludis use this rsync : rsync://gentoo.zugaina.org/steam-overlay-portage
If you have a problem : ycarus(-at-)zugaina.org