I am sure we have all created some utility helpers for doing this type of thing before but this class written by Sebastian Rehnby provides a great, animation aware category for performing various types of adjustments to view frames (moving, resizing, centering and aligning).
This is a great explanation of how explicit CAAnimation animations work from Ole Begemann. Overriding the implicit animations is a great technique that I don't see used often enough, not perfect for every situation but this post could remove a large number of uses kCAFillModeForwards from the world.
This is an interesting one from Justin Spahr-Summers, a library to extend Objective-C to explore some new language features. Important to note that he calls this a proof of concept rather than something you should be using in production code but the ideas in here are certainly very interesting.
Reda Lemeden with more talk on the pros and cons of pre-rendered assets vs Core Graphics drawing. Reda suggests using a hybrid approach of using Core Graphics to render resizable assets. Also check out the comment on the post from Andy Matuschak of Apple for some clarification on off screen rendering.
More UIActivity goodness from Simon Whitaker, this time a Dropbox SDK aware activity.