Back when the "Star Trek" TV series debuted in the 1960s, viewers watched in wonder as Captain Kirk traipsed around on alien worlds, talking into a tiny hand-held communicator device that he pulled from his pocket. Several decades later, we've all got smart phones that do pretty much the same thing. Which of the imagined 23rd-century gadgets from the original "Star Trek" and its movie and TV sequels remain futuristic, and which technologies have already been invented?