Right... I fumbled around that idea a little.... Here's what I was able to search on this site, and from some common knowledge:
a table called UserLogged...
Inside it will be fields:
ID (PK)
UserID (FK)
loggedIn enum('0','1')
loginTime (dateTime)
Every time a user successfully logs into the system, this table will be updated.
A CRON "Job" will then need to be run continuously, setting all the loggedIn values in the this accounts table to 0, and updating it with the current users logged in...
Can anyone point me to some good references on CRON... or perhaps some code and guidelines to get me started on this new land of programming?