Nanotechnology or molecular engineering (precision manufacturing at the atomic level) will enable us to produce dirt-cheap supercomputers, ubiquitous 100% pure water, highly cost-efficient solar energy collectors, and myriads of other world-changing technologies that we probably have not even imagined. Most of us are not aware of advances in miniaturization technology that suggest we're not so far away from being able to produce automated nanoscale factories, yet futurists such as Ray Kurzweil expect a nanotechnology revolution within a couple decades of the present.
Below are some images of our nanoscale world, taken by British scientists using scanning probe microscopes that can infer the positions of individual atoms.
Laser-Created Crater on the Surface of a Sapphire
E Coli Bacterium
Twelve Artificially-Arranged Bromine Atoms
More images are available here: