Nick Farina on building an imitation of the MapKit style callout control. He describes it as painstakingly recreated and I would have to agree, the level of attention to detail is seriously impressive. This is the kind of quality of open source control that I love to see being built for iOS.
Rasmus Andersson with an interesting TCP over USB library for allowing an iOS device to communicate with a Mac using a USB the 30 pin connector. When I first saw this I figured it might need Jailbreak but I just tested it and it doesn't, happy days.
Mattt Thompson talking at the New York iOS developer meetup talking about 5 lessons learned from the ongoing development of the open source AFNetworking library. From pull request comment novellas on thread safety through to dealing with multiple JSON libraries this is a really interesting look at keeping the design of a popular open source library on the straight and narrow.