area31-ebuilds
1- RTFM
http://www.funtoo.org/Local_Overlay
2- Get this overlay:
# mkdir -p /var/overlay ; cd /var/overlay
# git clone https://github.com/area31/area31-ebuilds.git
# mv area31-ebuilds /var/overlay
3- Configure /etc/make.conf:
# echo 'PORTDIR_OVERLAY="/var/overlay/area31-ebuilds/local"' >> /etc/make.conf
4- Update your Portage Cache (eix database):
# emerge app-portage/eix
# eix-update
5- Keep updated:
# cd /var/overlay/area31-ebuilds && git pull