How get subscribe to user flag on a node I have a node for example news
I have Message module installed
I've enabled the flag subscribe to user 


I want people to be able to subscriber to
a user. To get updates on thier latest post.


I want to add the subscriber user flag to the node template for 


This is what flag module suggests to do

Placing a flag link on a page 

$account = menu_get_object('user');   
print flag_create_link('fools', $account-&gt;uid);


How would I add this to a node?
You could create a block with a php filter or create a custom template for that node. You can also alter that node from from template.php

http://www.webomelette.com/altering-node-content-it%E2%80%99s-rendered-page-drupal-7