Search Engines and PHP

I was wondering if anyone can enlighten me about the ability of search engines to read and list PHP pages. I have been told that because PHP produces a dynamic html page (i.e. one that possibly outputs different HTML for each hit or request) that they are not easily added to search engines (if this is true though what would be the point of having any html pages if you can't update or change them at anytime?). Another point was made to me was that many PHP pages require additional commands to be passed through the URL eg www.domain.com.au/writestufft.php?variable=foobar which search engines find hard to deal with also. If any of these are true or if there are such problems which could result in the page not getting listed then what are the options. My only idea has come from the [PHP]url hide thread in which a index.html single 'wrapper frame' could be applied to the entire site. Any Ideas Jamie Slightly confused and possibly mislead