Ed. Note: It's "Food Day" on the SciAm guest blog, and bloggers around the network have also been sharing their thoughts on our relationship with modern foods. A year ago, AiP ran a series on coffee. It took on a life of its own, and spurred several follow-up discussions, which you can read here. In honor of "Food Day," I've resurrected and edited the original series that started it all. So go brew yourself a cup of java and settle in for a look at the role coffee plays in our lives.