Just a little update - feel free to add requests as I'm nearing completion.
-Date picker now supports time as well, date and time prefab available. GetCurrentDateTime() to retrieve the selected date and time as a System.DateTime struct.
-Following ArenMook's suggestion, dropped compatibility with NGUI free. Upside : delegates are now used, resulting in better performance and flexibility.
-Delegate implementation means it is now easy to build compound pickers : picker element can now contain any number of sprites or labels. 3 sprites, 2 labels - 4 labels, 2 sprites - whatever you need is possible. Prefab included features 2 sprites and 1 label : item sprite, price label, and currency sprite. Think : orc armour boots sprite (item sprite), 4 (price label) gold coins (currency sprite).
-Tested performance on iPhone 4 ( not 4gs ) : 60 fps with the demo scene, lots of pickers in there!
-Code structure improvement : the PickerManagerBase class implements the Template Method pattern - meaning you can learn about design patterns, but also easily extend the class for custom behaviours. Design Patterns are definitely in!
Cheers,
Gregzo