One of the coolest things about Star Trek is that the technology has always been loosely based on reality instead of total science fiction. I believe they call it science fact. Some of the stuff is way out there and other stuff has already been surpassed by us. Take the communicator for example. They had clunky communicators on TOS. My iPhone is so much more powerful than their device. Other things aren't even close, such as warp drive.
POver at bestcomputersciencedegrees.com they decided to put together an infographic about some of the more famous tech in the Star Trek universe and show how close we ar and how infinitesimally far away we are. In the infographic they go over things ranging from impulse engines and shields to transporters and holodecks! Enjoy!!: