Because they have to see it to believe it.
Magnifying tools for presenters.
My personal favorite:
Virtual Magnifying Glass
More features, but also more hassle:
Zoomit
Words to pictures.
Flowcharting tool that runs in Excel and turns words into a flowchart. FlowBreeze
Plug space for both of your scientific calculators.
This cool device from 360 electrical has rotating wall outlets.