Multiple Heroku accounts

Install the heroku gem if you haven't already.

$ gem install heroku

Next install the heroku-accounts plugin:

$ heroku plugins:install git://github.com/ddollar/heroku-accounts.git

Setup your own personal account for your own projects:

$ heroku accounts:add personal --auto

Then setup an account for each of your clients/work projects:

$ heroku accounts:add work --auto

Navigate to the project folder (personal, work or otherwise) and set the default Heroku account to be used:

$ cd projects/personal
$ heroku accounts:set personal

Now you can have multiple Heroku accounts without messing around with your SSH keys.