I’ve added my fancy-schmancy more accurate UISlider and ShapeUtilities (which converts illustrator data into a cocoa CGPathRef) to Github! Check them out here:
They are both standalone Xcode projects that will run on iOS 4 and greater. They have nice READMEs and commented code. If you would like to clone and improve these, please feel free. Also, let me know if you do that! They aren’t under any kind of license at all so do what you feel like doing.