It's an NSConference themed email this week mainly because it's where I spent most of my week. Another highlight was Robert Wija's talk about his open source styling framework for UIKit controls. Built on UIAppearance, it uses a plist format (rather than some of the CSS inspired projects that do similar) to specify the styling and I really like Robert's approach to this problem.
Sam Vermette with a nice imageless version of the radiating map pin control seen in MapKit. It's always nice to see artwork source files included in a project like this and in this case they are PaintCode files which is great if you want to customise the look and feel of the project.
Yichao Ji with an implementation of a ternary search tree in Objective-C. As mentioned in the readme for the project this makes a great companion to HTAutocompleteTextField which was mentioned back in Issue 79 of iOS Dev Weekly.
Justin Williams with a work in progress project to build composite image filters by specifying "recipes" in JSON. This should make it significantly easier to add that must have Hipstamatic inspired filter to your app. Quite an interesting name for the project too :)
One of the big downsides with custom drawRect: methods is that they are inaccessible by default and until Apple figures out how to translate CG drawing commands into a description of what is being drawn (come on Apple, what are you waiting for?) then we have to do a little extra work to add that metadata to our controls.