The tricorder was a handheld device that sampled environmental conditions around the user and/or gathered data about specific objects for the user. The typical use was to insure that the atmosphere/surrounding area was safe to be in and to analyze various objects or areas to gather data for investigative or decision making purposes. Today we have widgets that allow us to do much the same thing with our smart phones. Using a software program called Layar, you can find out what surrounds you, as far as businesses, landmarks, etc. in a given area. Using a weather widget you can get environmental data to include temperature, humidity, precipitation predictions, reports on precipitation amounts, etc. With some minor add-on technology pieces and accompanying software, you can use the smart phone to sample air and analyze it for toxins and you can even use it to monitor the vital physical indicators of a given individual to include heart rate, respiratory rate and blood pressure.
But our technology advancement has not just been in communications or data transfer / data delivery devices. We've also made advances in weapons. In the mid-1960s when Roddenberry foresaw the phaser - a handheld weapon that delivered energy to incapacitate the enemy - TASER didn't even exist yet. But, again less than 50 years later, not only have we seen the evolution of the TASER but we've seen evolutions of the TASER design that mimic the evolution of the future phaser design.
Both started out as relatively bulky pistol-appearing tools. The biggest differences being that the phaser had an adjustable power setting and used no wires to deliver the energy to the target. TASERs do use wires and are designed to deliver a single type of energy burst in a given TASER product.
Then the pistol-appearing tools became more streamlined; sleeker; smaller; but just as capable and potentially even more efficient.
Finally they both transformed from pistol-appearing to something less obviously recognizable as a weapon; something that resembled a handheld electric razor or a bent television remote control.
All of these advances have occurred in less than fifty years - not taking anywhere near the 200 years Roddenberry wrote into this Star Trek stories. My concern, with that realization, was a wonderment about what another 250 years of human evolution will bring and whether or not the law enforcement profession will even exist in 2266? I take faith that not only will law enforcement still exist and be necessary but that we'll evolve in ways we haven't yet seen. Why do I believe this? Because Roddenberry saw it too.
On the Enterprise-D in Star Trek: The Next Generation, there was Ten Forward - a BAR. On Star Trek: Deep Space 9 there was Quark's Bar. Let's face it: as long as humans (or other life forms) get intoxicated on alcohol (or whatever does it for them) police will be needed. Stupidity and lack of judgment increase with the consumption of intoxicating beverages.
And in the most recent Star Trek movie, a young James T. Kirk gets chased by a motor-cop - albeit the motor-cop is riding a FLYING motorcycle. There's something you motors guys can look forward to.
So, if you're s Trekkie, keep all that in mind as you watch the newest release, Star Trek: Into Darkness, when it comes out this month and pay attention to the science-fiction technologies that might well be science-fact sooner than we think. If you're not a Trekkie... get enlightened. :-)