yup, each time a new record in the databse.
on the profile page of user A, you just take out all record where the user is A and write them down through a while loop.
It's just like you would do a forum thread, so if you need examples, there are enough basic forum scripts on the internet, so take a look at those codes.
and don't forget:
www.mysql.com
www.php.net
www.google.com
are your friends
.
Crebilis