Syndicate Specific Elements: For Example: Total Registered Users

Hey All,

I've been experimenting with syndication and it is pretty fun: http://punbb.org/docs/dev.html

I noticed I can pull in "general stats" but I haven't found out how to pull in very specific data, for example:

How do I pull in the total number of registered users into a php page?

I've got another good one:  I'm integrating punbb into my CMS... how can I pull the following into the member's pages:

Show your posts
Show your subscribed topics
Last 5 posts by member "XXXX"

Now that would be cool!