I have been working with Status.net to provide a science-oriented, free, non-commercial microblog (similar to Twitter, but open-source and without the noise).
You can see the latest status updates at http://science.status.net.
All the normal methods for subscribing to updates should work in your favorite Twitter-like client or service. Since this service is based on federated open-microblogging, there are a variety of ways to include science-related status updates in your daily feed.
To contribute your own science-related news and other tidbits, click "Login" in the upper-right (you can even use your existing Twitter or OpenID-compatible login ID). Once you are logged in, you can subscribe to the general feed (@science) or to individuals. To post an update for public consumption, include "@science" somewhere in your message.
Thanks for checking out the service, and I hope that you find it useful.
-Dan S (science.status.net editor)