/me<space><rest of message>
will show:
* Sunshine rest of message
Also have a look on
http://www.msgpluslive.net/features/ and/or look at the commands list that drops down when you type / in a conversation. Make sure you enable commands in Plus > Preferences > Conversations
Edit: you're welcome...i'm sure there was a list of commands somewhere but i can't find it right now.
Edit2: found where the list should be,
http://old.msgplus.net/help_cmdtag.php
Even tho this is for Plus!3, most tags and commands are the same..hopefully the site will come back up again...
/ 
