Possibly one of the coolest of the many cool gadgets in Star Trek is the replicator. Imagine being able to get any item - or meal - you want, exactly the way you want it, with no trip to the store or waiting in line.
Need some clothes for a fancy date? They're ready in seconds and fit perfectly. Want a toy or musical instrument? No problem. Craving some comfort food? Just ask.
Unfortunately, the Star Trek-style replicator probably won't ever happen - at least not for a long, long time. However, there's something close and it's already here.
I'm talking about 3-D printing, and it's going to change the world. Before I talk about that, though, let's get started with a little background.