I would like to be able to add annotations to slides that only I (the presenter) can see on the iPad, while the audience sees a clean version without these annotations. This would allow functionality similar to the "presenter notes" function in powerpoint, but it would be better because the notes/annotations could be placed beside or layered over the related text/objects seen by the audience.

I could use this to remind myself to discuss aspects of the slide in a particular order or add a reminder in the margin to make an important point or draw an arrow to remind myself to make a connection.