These are freely available datasets from here and around the world. Some are accessible via API's, which are an automated way to mine data into software like Google Refine.
Some of my colleagues started hassling me about how this blog was dying from neglect, hence the rush of posts (or reposts from my other personal blog). Sorry. Here's one for the weekend, or maybe not. I'm obsessed with podcasts and I think libraries could be making more use of them.