For those who want to install FeynDiagram on their own Linux PC's, this software may be obtained from ftp://hep.itp.tuwien.ac.at/pub/FeynDiagram/. Just follow README_installnotes therein (the Makefile is already updated to fit to Debian systems.
Once installed, see 'man feyndiagram' and '/usr/local/lib/FeynDiagram/Docs/tutorial.ps' for documentation. Examples are found in '/usr/local/lib/FeynDiagram/Examples', where a convenient makefile for invoking FeynDiagram is included.
News: There is now (2003) an official website for the (still freely distributable) FeynDiagram package, http://feyndiagram.com, where a newer version (2.5) can be downloaded.