Last week at a New Tech Meetup, I got a preview of Radio Handi, a company that's rolling out some useful group communication services. The one I like the most is the free phone conference system that uses e-mail for setup. You e-mail a note to the people you want to have a phone conference with and BCC "invite@radiohandi" as well. Shortly, the Radio Handi bot e-mails all the attendees with the dial-in bridge number.
Why it's great: there's no previous sign-up required, you don't have to set anything up on a Web site, and it's free. Well, sort of: the call to the conference bridge is in the 712 area code in the United States, so toll charges may apply. There are also 30-plus international numbers. The service is also available directly via a SIP-based VoIP network (but not Skype, unfortunately).
There are several free reservationless teleconference services, but Radio Handi is the only one that I know of that lets users bypass the Web sign-up if they want, and do everything by e-mail.
Radio Handi will soon be adding other services, such as a feature that can turn any phone conference into a live MP3 stream. That makes any cell phone essentially an Internet radio station, which is pretty cool. That should roll out this week. Also, the company is buying a big block of phone numbers and may eventually give out temporary-use phone numbers for conferences, instead of a number and an access code. That will make conferences easier to dial in to.
The service also has text features. It lets users manage e-mail and SMS discussion lists and can turn SMS into a group chat (see also: 3jam).