[dmragone]

Learned a great trick from my old boss who gave a lot of powerpoint-based presentations. He would frequently add a "black" slide (as in nothing on the slide, completely blank, just one big block colored in as darkly as possible - a good alternative is to hit the "b" key on your keyboard) when he wanted to people to stop looking at the deck and focus on him.

It was amazing how everyone's eyes would go straight to him when that slide came up - they had nothing else to look at, and he could make a strong point, knowing everyone was paying attention for the next 15-30 seconds.