You could always turn up with a huge pile of OHP slides......
I'm surprised that CIS-Plod didn't tell you that even unformatted floppy disks could be "Han sickurity risk, ho-yus"....
The infuriating projection systems some parts of the RAF use cannot even be connected to an external speaker's laptop these days, it seems...
They never have the correct cables and even if you supply one, there's inevitably a faff with blue screens and bemused audiences as 'INPUT SEL' and other geek-hieroglyphics appear on the corners of the screen to muted applause, whilst various attempts are made by increasingly senior officers grappling with a remote control of unfathomable complexity (and flat batteries) to persuade a picture to appear on the screen!