With this WP-Theme called Prologue (yes it was difficult for them to zip the file) you can turn any wp-based blog into a community-twitter-like-blog (see pic below).
I have zipped the file and put it at http://www.adesblog.com/files.php, see Fav WP Themes folder.
You can see Prologue powered blog demo here.
Basically how it works is when someone has the ability to post to a blog they see a short form at the top of the home page with a post box and tags. There they can post short messages about what they’re doing.
Below the posting box is a list of everyone’s latest tweet or message, with their Gravatar next to it. You can click on an author to see all their messages, or a tag to see all of the messages in a given tag (which we use for projects). There are RSS feeds for everything: the entire prologue, each author, each tag, and even combination or searches can be subscribed to in your RSS reader. source
This theme is very suitable for like-minded group of people or friends to use it as a platform to communicate and stay updated with each other. You could use Facebook or Twitter for the same reason, but most of the time your Facebook and Twitter accounts get crowded with people you don’t even know.
So, if you want to create a twitter-like site for your friends only, then Prologue is — it!
I like this new tool a lot – ive been using it on some of my blogs for a little while now.
I’m planning to create an open community for beginners to share their experiences on another sub-directory using this great theme.
Hopefully, it doesn’t take too much of customization on my part.
Can you add Prologue capability to an existing WP blog with a different theme?