I am usually the person saying that you shouldn't go creating your own gesture recognisers (for usability rather than tech reasons) but I think this article by Thomas Mellenthin this is a perfect example of where a custom gesture is exactly the right choice.
Nick Harris with some code for recreating the slide out navigation seen in several iOS UIs recently by animating an image view with a screenshot around. I have been doing some experimentation with storyboard segues recently and there is so much you can do with Core Graphics/Core Image and a simple screenshot of a view controller.
Want a lightweight Objective-C wrapper around SQLite? Look no further than FMDB by Gus Mueller which hit the big two point oh this week.
Brad Larson released an interesting library this week for doing customisable Core Image style effects with OpenGL ES, oh and for extra bonus points it is also compatible with iOS 4.
Just in case you suddenly decide you are in need of an easy to use hashing class, Karelia software have a nice open source class for generating a SHA1.