Is it possible to customize the brushes that appear in the marking menu?  I know that you can tweak the parameters of the marking menu brushes, but can you assign a brush from the brushes palette to the marking menu?  If not, could you please make this possible?

Also, it would be nice to have more undo levels.  10 is not very much.  Particularly the iPhone 3GS should be able to facilitate more.  I love the application, and it shines in many areas, but in this area, all the other major contenders have many, many more undo levels.