i was wondering, how would i go about setting up a php code such that when someone enters a url into a form i would like to extract the name of the webpage and a photograph similar to what happens in facebook when you put a link on someones wall, you get the title of the link and picture. Do i have to read an rss feed or what ?
Rss feed are XML therefore you should be able to DOM or SAX in conjunction with Xpath to retrieve these informations by hand.
Zend_Feed provides an easy way to work with feeds (either RSS or Atom).
$feed = Zend_Feed_Reader::import('http://www.planet-php.net/rdf/');
$feed->getTitle();
Concerning the preview picture, I don't know any free and out of the box solution.
You can take a look at thumbshots.org which provides free thumbnails for websites which in DMOZ but requires a paying subscriptions for others.
You can also try http://www.guangmingsoft.net/htmlsnapshot/html2image.htm which is well know and available on Linux, but still not free.