Want your own Twitter? Check out Laconica

Laconica (pronounced "luh-KAWN-ih-kuh") is a Free and Open Source microblogging platform.

It helps people in a community, company or group to exchange short (140 character) messages over the Web. Users can choose which people to "follow" and receive only their friends' or colleagues' status messages. It provides a similar service to sites like Twitter, Jaiku, and Plurk.

This is definitely an option for those of you looking into corporate micro blogging ;)

Try it out on-line at: http://identi.ca/
or download you own copy at: http://laconi.ca/trac/