What I'm talking about is something like htttp://www.untorch.com<p>I'd use this but it gets a little too cute by trying to make you refer 5 friends to sign up before you can try anything with the product.<p>Thanks
Not sure if I understand the question entirely, but have you given LaunchRock a try? It gives each signed-up user a unique URL to share, so you can track who your power-users are, etc.<p>Hope that helps.