A product of Brother, the company best known for its printers and multifunction devices, OmniJoin comes billed as "online meetings that don't feel like online meetings." OmniJoin isn't that radical a reinvention of online conferencing, but it works pretty well, barring a couple of hassles.
There is no free tier; the basic version is $49 per month per host, but that edition is pretty well equipped. Up to 30 attendees can join, with up to 12 of them sharing 720p camera video streams. There is no limit on the length or frequency of meetings, either. Higher tiers raise the number of allowed attendees, the number of video streams and video quality (up to 1080p).
OmniJoin currently offers Windows and OS X clients; there are, as yet, no mobile clients. OmniJoin claims to support high-end videoconferencing hardware (e.g., Sony PTZ cameras, ClearOne audio systems) for those who have access to this equipment.
The Windows client uses Office 2010's visual styles (ribbon menus, etc.). I found a number of useful features. Most prominent is the built-in ability to record meetings -- actually, the ability to record all client screen activity -- and save them to an MP4 file. Another handy feature: The ability to import a Microsoft PowerPoint document directly into the chat client and share it with the other attendees.
Other tools include a whole mini-suite of bandwidth- and network-assessment tools, which can be used to figure out if a balky chat is because of your computer, your connection or some other issue. Screen and application sharing is also available, and a shared application (or screen) is distinguished by a bright green border and a dedicated palette of tools for annotation. The quality of the visuals for the shared application can also be ramped up or down for people on faster or slower connections.
The biggest gotcha with using OmniJoin, at least in this version, is the way meetings are configured by default to use a dial-in phone bridge, not VoIP, for audio. This isn't hard to address -- you just need to edit the default settings for your meetings on OmniJoin's website -- but it was a bit perplexing, and it would have been nice to have control over such things from within the client app itself.
OmniJoin's a solid product if you're willing to live with a couple of host configuration quirks. Especially useful are the ability to record conferences locally and to share PowerPoint files without additional tools.