We will not talk about what the concept is all about, because there's plenty of good articles over the net. Also we won't talk about trying to determine where could that digital currency go from here - Up, after a %600 pop? Maybe down to 0? No one really knows, and honestly, the tools and history data simply isn't enough in order to establish a sound mid/long term analysis.
So how can one make money off of Bitcoin without an expensive crystal ball?
The answer lays in the current nature and structure of the Bitcoin trading arenas. Unlike regular currencies, which trade through sophisticated trading desks and grouped/central systems that share data of the last trades in a real time, Bitcoin is different. That digital currency has only few trading exchanges over the world, and data is not synchronized between them. The implications of that fact is that arbitrage trading as an outcome of bid and offer discrepancies is quite common and easy to trade. For example, a Bid-Ask on .Net exchange is $800-$810, and at the same time, on MtGox the bid is $809-$812. The requested action is clear, Buy at $800 and sell immediately at $809. For the thechie among you, an automated system could be developed for an automation process.