Ridley Scott's Blade Runner is easily the best science fiction film ever made, and the only film based on Philip K. Dicks writing that is actually any good. It's coincidentally the film I've seen more often than any other movie, since I spent a disproportional and unhealthy amount of my adolescence in love with Roy Batty.
We're going to take a look at two gadgets this week, first off is the Voight-Kampff Machine. Combined with a series of questions about wasps, evil children and your mum, this tests whether you are human or actually a replicant - an android slave built to do the rubbish jobs. The test measures the subject's empathic response to the aforementioned questions, looking for 'flattening of affect'. A fundamental and pretty obvious flaw of the machine is that it works on the principal that human beings necessarily possess some level of empathy for others.
In the book (Do Androids Dream of Electric Sheep, in case there is a single person reading this who doesn't know that) the machine is made up of a unit operated by the person asking the questions, a light beam which measures pupil dilation and a cheek patch which measures your blushes. In the film it's just the eye beam.
The Esper Machine isn't in the book at all, but is one of the most aspirational movie gadgets ever. Deckard, whose job it is to hunt down the escaped replicants, uses the compact, voice-controlled computer to analyse a crime scene by using a photograph. The Esper turns a photograph into a three dimensional capture of an event - enabling you to zoom into a high resolution picture, and navigate it - Deckard uses it to look round a door to see one of the replicants. And people are impressed with 3-megapixel cameraphones?