Discovery: ~/.ssh/config 

I’m probably the last one to know about this gem, but it sure has made my life easier. I have like 4 or 5 random ssh keys to keep track of that map to various users on various systems. Up until know this has meant passing the write key file with the -i option to SSH, but no more; ~/ssh/config makes life much easier. All you have to do is define which sites go with which user and key and ding ding life is good.

    User root
        IdentityFile ~/ec2/example.pem
    User gitosis
        IdentityFile ~/.ssh/id_rsa