There's plenty to it! The algorithm is actually pretty long... but it's just based on which stocks people are buying... so if a lot of people buy one stock, it's value will go up (because the demand for it is increased) and vice versa.
Yeahe exactly.. if someone wanted to take on the responsibility of maintaining stuf like that, then that'd be cool. Read 'Site Updates/Potential Problems' for my view on it.