If you loved the replicators Gene Roddenberry introduced in "Star Trek: Next Generation," you should be following the work of all of the folks building out the budding "personal fabrication" industry. Yesterday I ran across this great summary of the various different technologies involved in turning the bits that course through the network into atoms.
This trend is a big deal for 2 reasons. First, as we get closer to bridging the virtual and the physical in all sorts of ways, from exporting the objects we create in virtual worlds to building sensor and actuator based projects that interact with the physical world, the need for custom parts of all shapes and sizes only increases. If we are really going to go through any kind of a physical computing amateur explosion of creativity (as we have multiple times in software), the technologies of custom manufacture need to become accessible to the typical garage tinkerer. Example: the other day, my friend Andy and I were talking about an Arduino-based robot platform and he very quickly descended into talking about "lots" of 5, 10, and 20 thousand which frankly gives me hives.
The second reason why it would be good for hackers, makers, and startups to focus in this space is because small-scale replication appears to be such a disruptive technology that none of the big companies are paying much attention. Working where I do, you'd think that I'd see tons of 3D printing projects sprouting up. Sadly though the reality seems to be that most of the folks I meet on the inside dismiss it as a fad which is nowhere near being applicable beyond a few very specialized industrial verticals (I bet someone probably through the same about vaporizing ink droplets and shooting them at high-speed at paper 25 years ago in the age of toner, but that is a story for another day).
Personally, I am about one late night away from trying to build one of these in my basement. If it wasn't because I have serious doubts about my own mechanical abilities assembling a project as complex as this one, I'd be happy to usher in the era of Skynet with self-replicating robots coming straight out of my basement!