If you want to use the Ecofont for Linux, these steps work in all modern distributions (like Ubuntu and Fedora):
1) Create a directory to hold your "misc" fonts under /usr/share/fonts. Can be /usr/share/fonts/miscttf. Copy ttf file to it.
2) Run the following commands:
ttmkfdir mkfontdir fc-cache /usr/share/fonts/miscttf
(Special thanks to Juan Carlos Castro y Castro and Willem Bogaerts)