Twitter Inc. has launched a mobile version of their Twitter service. It presumably is meant for mobile devices to be able to access the twitter service directly through the web interface without any 3rd party client needed. We briefly checked it out and it looks to be a pared down version of Twitter formatted for mobile phones.  Here are some screenshots of the new service (taken from a Mac on Firefox 2). 

Twitter Mobile - Login screen 

Twitter Mobile - Logged in and sending messages

Twitter mobile is available at m.twitter.com