Feeds --- Feeds of various sorts have been a feature since you could first subscribe to blogs using various forms of RSS. Let's call a feed a sequence of published things such that you can subscribe to, with in some cases a mechanism to inform you when the is more added to it. So a feed by itself is a one-way thing with no feedback. While blog feeds were the rage at one point, podcasts took over the limelight with the eponymous iPod, and now it seems people happy move in between, and sometime...
