additemtodock allows you to add items the dock on Mac OS X systems via the command line.
Further information including basic and more advanced usage is available via the following URLs:
Home page : http://www.lucidsystems.tk/tools/additemtodock
Introduction : http://www.lucidsystems.tk/tools/additemtodock/additemtodock_introduction.txt
Usage Tips : http://www.lucidsystems.tk/tools/additemtodock/additemtodock_tips.txt