Agree 100% with JorgeM. Scraping other people's stuff is just theft unless you have consent, and you shouldn't do it. In addition, scaping sites has its downsides too - you are totally at the mercy of the site owner as to whether you s/he will continue to maintain the data in the same format or even at all.
An API is far friendlier. One word about file_get_contents - it may not always be available on your host as some disable it. In this case you need to use cURL.