A few days ago I got a demo of Joyent from the company's CTO, Jason Hoffman. His Web service is an e-mail application, calendar, contact list, and file storage for small groups. It's similar enough to Outlook and to existing online e-mail applications that it's easy to grok, but it also has tweaks on the standard model that could make a difference for business customers.
It starts with Joyent's security defaults. The default privacy setting for everybody's e-mailbox is "wide open." Anybody in the team can peek into anybody else's mailbox. It's what Hoffman calls "cubicle security": you trust your coworkers not to snoop on your desk, but if they need to do so they can, and they could save your bacon and the company's if you're on vacation and somebody needs that one piece of data that's on your desk. Users can lock their e-mailboxes easily enough (Hoffman's own e-mailbox is locked from his employees) and also set access by person or by item.
The security defaults are whacked, if you ask me, but Joyent gets a big thumbs-up for its clever handling of e-mail reply threads. On a group message, instead of replying to all and participating in an unruly thread of messages, you can reply via a comment field at the bottom of the message and send a pointer to the original message--now with a managed discussion thread appended to it--back to the recipient or to the group of people who are CC:'d on it. This is much cleaner than the standard way we handle e-mail discussions.
Also clever: All items in Joyent--messages, appointments, contacts, and files--can be given tags, and users can subscribe to these tags on their Joyent desktop. This amounts to an extremely quick way to create project workspaces made up of e-mail threads, files, and appointments.
The two big downsides of Joyent are that there's no offline version of it yet (although the Joyent server is standards compliant; the e-mail can be accessed by IMAP clients, for example) and that its cool tools don't easily extend to people outside your company's installation. Also, in my testing, the application was a bit slow.
For a small company or a start-up looking for a hosted e-mail system, especially a company that doesn't want to buy in to the whole Microsoft Office/Exchange ecosystem, Joyent is worth serious consideration. It costs $15 to $100 a month, depending on the number of users.
For a deep and in-person look at Web 2.0 applications in the office, come to the Office 2.0 conference in San Francisco on October 11 and 12. CNET is a sponsor, and I'll be speaking at the event.