PHP-XML Weather
This is a sample to illustrate how one can use PHP and cURL to access an existing XML feed for US weather. It grabs both current conditions and a nine day future forecast based on the zipcode that one enters. Unlike a lot of other PHP weather tools, this one doesn't screen scrape from yahoo or pirate MSNBC's feed... so, while it can only do US weather, you can do it with a bit of peace of mind.