Specifying Specific SSH Keys for Git Remotes

When using Git via SSH with services such as GitHub and Gitorious, it can be useful to use specific / different ssh keys than your default.

This is accomplished with an entry such as the following in your ~/.ssh/config:

Host some-alias
    IdentityFile /home/username/.ssh/id_rsa-some-alias
    IdentitiesOnly yes
    HostName git.example.com
    User git

You then specify this remote as follows in .git/config:

url = some-alias:project/repository.git