In quite a few ways, Apple's iPad and iBooks announcement today was a shot across the bow of Amazon's Kindle. Sure, Apple played nice, even saying that Amazon has done a "great job of pioneering" the e-book space, but you can't help but think that Apple thinks of itself as the evolution of the Kindle, not mere competition. Steve Jobs says that Apple is going to "stand on their shoulders," and that doesn't sound quite as benign as perhaps he meant it. So, how do the devices stack up, specifically as book consuming devices? Well, for starters, one of these things costs a whole lot more than the other... let's break it down after the break.