I’ve been looking at some simple ways to add a backchannel for a conference, with a few major constraints. It has to be free or very low cost. It should not be open to the general public (thus eliminating Twitter). It should be as simple as possible.
The simplest tool I found was Today’s Meet, which lets you set up a backchannel in seconds, requires no account set-up, allows pseudonyms, is web-only, provides a full transcript and will delete all contents after a set time. Pretty good for a free service. One main issue could be that the site is not password protected. There is a unique URL generated and if kept confidential, is acceptable for low risk conversations. The site can be set up minutes before the conference and transcripts downloaded minutes after the conference is over and then deleted. Overall, a rather stealth technology.
A more complicated, but also more robust platform is WordPress. It requires each user to create a WordPress account. Using the P2 theme, available with a free wordpress.com account, you can set up a private community activity stream that looks much like Yammer. Benefits include customization, the addition of explanatory pages and several widgets, including Twitter feeds. With the worldwide WordPress community, you also know the technology will be around and supported for a long time.
So these are two free options to use at conferences where participants do not want to be on the open web and have some concerns about security or publicity. These are not options where security is a major concern. In that case, stick to your Intranet or VPN.