How to make an RSS aggregator site ?
 

I start to think of programming one aggregator site in PHP.

The site allows the users to submit their site Feed address then the site have to track all updates from the site submitted.

Finally, i would like to create a feed for that aggregator site so that it could be used in various places to show the updates from many sites which have been submitted.

Generally i want something like Google reader.

I really need suggestions in order for me to have a some main clue to start everything up.

Please give me some ideas or some sources which i could use to accomplish the site described above.

Thanks in advance!!!

Parsing of the RSS feeds
DOM Document: http://uk3.php.net/DOM%20Document

Selection of RSS feeds
Al Jazeera: http://english.aljazeera.net/Service...31105943979989
BBC: http://newsrss.bbc.co.uk/rss/newsonl...t_page/rss.xml

What else would you require apart from some knowledge of RSS feeds? W3Schools can help you there.