Twitter is living up to its promise to open up its data stream as much as possible to developers. While I was negotiating with Twitter cofounder Evan Williams to sit down and do a video interview at Foo Camp last weekend, Gnip founder Erick Marcoullier was hitting him up to give Gnip, and therefore everyone, Twitter’s XMPP “firehose.” Williams was obviously in a good mood, because I got my interview and, as I just found ...