Buying books can get expensive. If you’re like me, you’ve got a collection surmounting that takes up more room than you should probably afford. So what are your options? You could use the library, but then you’re fairly limited in readings. Many of the classic timeless books will be around, but the latest and greatest will be a long time from hitting the shelf, if at all. You could do book trading, if you live in the heart of a thriving technical community. But, we don’t all have that sort of availability,...