bloomberg.com/energy/ Are they pulling the information from an API or something? How do I find this out? Thanks!
Possibly. Other than asking them? You don't. Whatever they're doing, it's being done on the server, not something you can see in your browser.
There is this man who runs down to WalMart and checks the prices on the shelves in the auto department for oil. Then runs back to his office and enters the prices into his computer. That's how.
Oil-price.net seems to be a good site to use. The data is pretty fresh (about 6 minutes old by my testing). You just grab the page and parse the price. cURL will do it, or you can parse the page out by hand, and find the data from the table that's just below the graphs (which are graphics, so much harder to get data from).
He runs down every 3 minutes, but they post every other price he gets. (Or he runs down every 12 minutes and they post each price twice.) 6 is an easy number to manipulate.