MessageDance has created a public messaging service for friends, like Twitter, but where you send messages by email that appear on MessageDance widgets on social networks, blogs and other sites.
You send messages from your email to your friends, by addressing emails to friends@messagedance.com. Among other things, it lets you write longer messages than competing service Twitter does, and it lets you include photos and videos.
With Twitter already popular, and existing email (or Facebook mail, etc) as a proxy that can be used to send longer messages, this service isn't bringing much terribly new to the table. I'm not convinced that most people want to email public messages to each other across social networks, instead of using existing options. In any case, MessageDance is still in private beta and a work in progress.
More details on how it works: You and your friends install a MessageDance widget on your social network profiles or blogs, then send email messages to each other from your MessageDance email accounts, attaching images and video you want to include. Excerpts of each message appear in a chronological stream on each person's widget. Click on a message excerpt in the widget and you'll be taken to the full message, on MessageDance's site.
I could see MessageDance being more immediately useful if it let you access your list of friends on Facebook within its own site. This would save you having to manually recreate a network of friends on MessageDance. The company says it is working on this.
As mentioned, the obvious competitor is Twitter, the site that lets you submit short messages, no more than 140 text characters, which appear in a running stream on its site. Twitter messages from you and other people can already be displayed on other sites. FriendFeed, for example, has done a great job of this. It combines Twitter messages from your friends in a running stream on its site, along with blog posts, YouTube videos and other information your friends share from around the web (our coverage).
Note: MessageDance also lets you email messages to Twitter -- a feature some have been asking for. While Twitter itself only lets you write messages up to 140 characters long, MessageDance lets you email longer messages to Twitter, including photos and videos. These messages to Twitter will be truncated after the first line or so, and include a URL that contains the full contents of the message, on a MessageDance page.
Besides Twitter, another obvious competitor is Facebook's status updates -- short messages you write about yourself that appear at the top of your Facebook profile, and in your friends' news feeds. As long as your friends are also heavy Facebook users, they will see your messages in their Facebook news feeds, as well as on your Facebook profile page.
Sunnyvale, Calif.-based MessageDance is self-funded.