How can I hide or fade out items?

Hi,

I've just started with Prezi and am creating a literal map identifying how our service works. However, I want to be able to change things like arrow directions to show a change in the way follow of information.

I have used the Beta "fade in" tool extensively (I would love to see this automated so I don't need multiple button presses), but I would also like to see a fade out tool.

I might be able to get over the issue by re-drawing items to cover up item underneath then fade them in, but it would be a bit of a hash.

Answers of a post card please

Chris