Here is an example of using a CATiledLayer to present a large, zoomable PDF in a UIScrollView.
http://olivetoast.com/blog/code/SimpleTiledScrollExample.zip
It’s about 50 lines of code in addition to what’s provided by the view-based app template.
If you’re wondering why UIScrollView zooming is designed the way it is, CATiledLayer might be the explanation you’re looking for.
Hope it proves useful to somebody!
Posted in: hamish