I have two github accounts, one for academic work and another for my personal projects. But Github identifies you by your ssh key, you commit account is nowhere written in email@example.com:perso/project.git.
Although Github staff don't advise us to have multiple account, I don't want to mix my personal work with the academic one:
Thanks for getting in touch. I strongly recommend that you do not use multiple personal GitHub accounts. Using multiple personal accounts often leads to confusion, and is almost always unnecessary. I recommend that you consolidate your accounts into a single account.
Thanks, James Dennes (GitHub Staff)"
Solution: Multiple ssh Keys and ssh Configuration
As github identities your account with the ssh key you use for the connection, you just have to create another ssh key:
$ ssh-keygen Generating public/private rsa key pair. Enter file in which to save the key (/home/kevin/.ssh/id_rsa): /home/kevin/.ssh/id_rsa_perso ...
and give the public key ~/.ssh/id_rsa_perso.pub to github.
Last thing, to greatly simplify the usage of that second key, tell ssh when to use it or not:
$ cat ~/.ssh/config Host github.perso HostName github.com User git IdentityFile /home/kevin/.ssh/id_rsa-perso
Now, ssh github.perso is equivalent to ssh firstname.lastname@example.org -i /home/kevin/.ssh/id_rsa-perso. So you can clone your personal repository simply by changing github.com to github.perso in the repository URL:
git clone `email@example.com:perso/project.git` # or just github-perso:perso/project.git