Automagically updating other peoples websites, when you're updating yours ?

OK, how would the others here do this :

If you had a particular website page with 1,000's of words on that page and there was one paragraph on it, that when I updated that particular paragraph, it automatically updated all other peoples websites, that had already wanted the updated paragraphs on their website and had already installed code on their websites for this to happen.

Keeping everything as simple as possible for the other website owners, and so that they couldn't tamper with the content of the paragraph in any way, how would the members here do that please ?

Any help appreciated.

Saz

I think you are after RSS feeds (http://en.wikipedia.org/wiki/RSS)

Thanks, it does look that way. Have looked at Iframes and includes, but RSS does seem to be the answer.