So I am building a kind of facebook wall feature for my website and have it setup to post updates using ajax.
What I cant figure out is once a user has posted a status update, that this update is then seen by other users online.
Currently, jquery picks up the actual status update, sends it to PHP through Ajax, PHP then inserts into the database and sends back a string / template / html with the post to Jquery where jquery then appends it to the current list of statuses.

But once I have made this update, how can this then be updated in all other online users?

EDITED: Typical, I make the post and then figure it out. Long Polling / web socket will do this. Run a setInterval and call a ajax request.