I was about to do a presentation in New Orleans on sustainable landscapes, but the session before me was taking place where my images will be projected. Normally, I'd set up my computer with my title slide, but that didn't work in this case. I could have turned the projector off, but then it would have to warm up. I could have put a piece of paper in front to block the image, but it's such a powerful projector I was afraid it'd set the paper on fire.
So it occurred to me: why not create an entirely black slide? So it looks like the projector was off, but everything was ready to go. Pro presenters probably know this already, but maybe somebody finds this useful.