Start numbering your slides from 0

Not that there's any good reason to do this, but you did you know you can start your slideshow numbering from 0 instead of the default 1?

Just go to the Design tab, click on the Slide Size drop-down and select Custom Slide Size...

Then proceed to lower the "1" to "0" under "Number slides from:" and voila:

Interesting? Useless?

Yes.