I think I know of one, but it's still in private beta :D - Rubin Sfadj

the part she likes is the list management, but also the ability to let beta users invite other beta users with a limited number of invites. if there are dashboard capabilities to watch usage, then this would be cool too. sorry, if this is the wrong room for this question. thx. - Brandon Zeuner

are beta services so common now that we need such tools? heh. Not sure i'd trust a service that couldn't code up their own really quick. - Ryan Gallagher

I really like the way that 12Seconds handles the invite process. Some features I hadn't seen before is the ability to view on the site when someone you've invited joins as well as revoking an invitation to someone so you can reuse it. I know 12 Seconds was built on Drupal and I just saw this Invite module which might be what they are using http://drupal.org/project... - Mark Krynsky