If you want to keep in constant touch with people,
find out what they are up to, as well as tell them what you are
doing, or if you need an immediate answer to a problem or issue,
then a micro-blogging service might be what you need.
There are a number of
micro-blogging services. These let you write brief text updates (of
up to 140 characters) and broadcast them. People then sign up to
follow your messages and you can sign up to follow others and
receive their messages.
Whereas many people can see the value of
micro-blogging as a tool to support informal learning, educators and
others are still exploring its use. Here are couple of useful
articles:
There are a number of micro-blogging services -
although the biggest and best known is Twitter -
www.twitter.com

Twitter lets you
write brief text updates (of up to 140 characters) and broadcast
them. People then sign up to follow your messages (aka "updates" or
"tweets") and you sign up to follow others.
You can receive information, news
and much more from colleagues, friends, celebrities, politicians as
well as companies and services. You can share your
own news, links or even ask a question of your followers. Tweet
about a conference or event
Here's a Twitter
Workshop by Jane Hart:
Using Twitter for social learning
See
How to use Twitter for Social
Learning
Twitter Reading lists:
Tools Directory Listing:
Micro-blogging/Lifestreaming tools