About a month ago, email assistant startup Cc:Betty renamed itself Threadbox and said it was rebuilding the product into a more work-focused collaboration tool. At 5pm Pacific today, users will get a chance to try out the new app, as Threadbox enters an invite-only beta testing phase.

Previously, Cc:Betty was supposed to help users organize email conversations and find the important content like documents and locations. You sent emails into the system by cc’ing “betty@ccbetty.com.” That was cute, but according to chief executive Michael Cerda, it also confused the people users’ were emailing because they had no idea who “Betty” was. The name was also a little too tongue-in-cheek for some business users.

Among other things, the Threadbox name signals a shift away from email — there are a few points of email integration, but most of the meaningful interaction happens on the Threadbox site, in real-time. Cerda compares the new application to Google Wave, the much-hyped, then much-criticized, collaboration tool. Basically, it’s a place to have a real-time conversation in a way that’s searchable, and again with options that help you drill down on specific types of content.

Cerda gave me a demo yesterday, and what impressed me about Threadbox is how fast and responsive it is. You don’t have to learn anything, it’s immediately obvious how to use it — you just start having a conversation and uploading and viewing content. You can see each participant’s presence via a green light that should be familiar to users of most instant messaging applications. You can run multiple threads, visible via tabs and pull-down menu, and flashing indicators tell you when there’s activity on a thread that you’re not looking at. And you can start private, one-on-one conversations with any thread participant.

And if you prefer email, you can still get an email digest summarizing a conversation, and post to a thread via email. Cerda said his team is also working on a Microsoft Outlook plugin that will turn any email conversation into a Threadbox thread with the push of a button.

Cerda told me the uses he imagines for Threadbox are independent contractors who want to coordinate with clients, as well as small work teams. He said he uses it to keep his investors updated. If you want to try out Threadbox yourself, go to the site at 5 and use the invite code “Venturebox.”

Cc:Betty first launched at the DEMO conference co-produced by VentureBeat and has raised $2 million in funding.