mac use multiple ssh keys for gihub
# ~/.ssh/config #activehacker account Host github.com-activehacker HostName github.com User git IdentityFile ~/.ssh/id_rsa_activehacker #jexchan account Host github.com-jexchan HostName github.com User git IdentityFile ~/.ssh/id_rsa_jexchan
Source: gist.github.com