859Using a non-standard key for ssh

How to log-in with ssh, using a non-standard key: 

ssh -i ~/.ssh/my_other_key username@host.server.org
1027SSH Key Permissions too open
982Mysterious SSH Connection Problem
976Git, Mac, SSH Keys and the OSX Keychain
950SSH, Keys and Cyberduck
941Local SSH Key via ssh-add
924Connecting via SSH and Key
829Digging a tunnel to a remote SFTP Server, Part 2