Ethiopic
The Resource page for Ethiopic fonts and input methods at wikipedia is agood place to look.
There are GPL'ed fonts availible for Linux also, please note though that there may be additions to the Unicode standard in the coming years, as languages in Ethiopia are completely analyzed and more linguistic work is done.
Other sites of interest on Ethiopic computing
The Unicode Standard is available in electronic form from the following web page.
http://www.unicode.org/versions/Unicode4.1.0/
There is some information about Ethiopic in the following document.
http://www.unicode.org/versions/Unicode4.0.0/ch12.pdf
There is a mention of Ethiopic on pages 4 and 5 of the following document.
http://www.unicode.org/versions/Unicode4.0.0/ch06.pdf
The following web page has links for code charts for many of the scripts used for languages.
http://www.unicode.org/charts/
There are three code charts for Ethiopic.
Ethiopic http://www.unicode.org/charts/PDF/U1200.pdf
Ethiopic Supplement http://www.unicode.org/charts/PDF/U1380.pdf
Ethiopic Extended http://www.unicode.org/charts/PDF/U2D80.pdf