Many MOOs are role play oriented.
You become a character, adopt a name and personality of your own. They're also great fun and by the star ratings below, you might get some idea of the great potential I see in MOOs for educational communication and projects that can be developed between students and teachers alike. People have emailed me confused about the technical set up. Here is a short list of 'life saving' URLS for those in trouble. Telnet and Client Programs is very useful.