How do I create test users?

Log in as the app using the email and pass you created at app creation. Make sure you activated the account by clicking the link in the email sent, then you can add friends with the app. These friends will then be able to add/view the app.

they don't have to be distinct humans. Just go to the myspace.com front page, "sign up" with a different email address, and that's a new test user, just like a real user. Invite them from your app's phony profile account, as described in the other reply. If you use different browsers (firefox & opera, for instance) you can have each logged into a different account.