Instalar Git server Ubuntu, con ssh-key

http://fclose.com/b/linux/1432/setting-up-git-server-using-gitosis/
http://fclose.com/b/linux/1434/managing-repositories-on-git-server-using-gitosis/
https://help.ubuntu.com/community/Git

Si da problemas pidiendo passwords:
http://www.baptiste-wicht.com/2010/07/tip-how-to-solve-agent-admitted-failure-to-sign-using-the-key-error/