that wasn't supposed to actually be part of the query, it's just an artifact from phpmyadmin
so...
SELECT `UserID`,`Name` FROM `LUM_User` WHERE `DateLastActive` >= (CURDATE() - INTERVAL 60 SECOND)
... which will give a list of users active in the last 60 seconds. of course, this needs refinement and additional code, and of course, the obligitory phantom users options...
i'd like to take this moment to prophesize. when the documentation explains enough for people to start writing meaningful extensions, this is going to explode. but i'm sure everyone that's here already can see that for themselves.