You can create test accounts through the API. I actually have a terminal script where I just write "fox" and it opens up a new Firefox profile with a new Facebook test user in it.
The URL is on my dev server, it creates a Facebook test user and then redirects to it. First you get an access token from graph.facebook.com/oauth/access_token, then you use https://graph.facebook.com/APP_ID/accounts/test-users to create an account using the token you just got.
