Magic has thousands of cards, about 10,500 according to Gatherer, and that number doesn’t include promo cards, alternate art, or tokens. There is a forum that is dedicated to scanning each Magic card ever printed, which is an enormous undertaking.
Each card is scanned in very high quality that lets you really appreciate the artwork (for all of your Vorthos out there). You can download scans of each set and submit scans that they don’t have. Collectively they call themselves the CCGHQ Team (formerly the MWSHQ Team). This is also the same forum that kindly hosts MTG Forge’s forum. The site Slightly Magic also host forums for other Magic projects like Wagic which lets you play Magic on your PSP or on Windows against the computer.
MTG Forge Forum