Well, the first thing you should look into is asking the owner of these sites for an RSS or XML generated feed so that you can not only parse the data easier(?), but also so that the owner knows your intentions and is expressing consent.
If you can't get an RSS/XML feed, ... I'm sure you could use some regular expression syntax along with [man]preg_match_all/man after pulling the HTML of the page into a variable using something like [man]file_get_contents/man.
But, to answer your question: Yes.
