Nanotechnology is the engineering of materials by building them up atom-by-atom, as opposed to making things small merely by carving up a larger piece of bulk material. The prefix nano- refers to nanometer, which is one billionth of a meter and is roughly the diameter of an atom. Thus nanotechnology requires operating at the nanoscale. This has only been possible in recent years due to scientific and engineering advances such as the scanning tunneling electron microscope, laser tweezers, and other exotic tools for manipulation at the nanoscale. It's still in very early stages of development, and little useful applications have emerged yet. It holds the promise of extremely small devices ('nanobots') for medical applications, where they could interact with biological molecules in useful ways. It also holds the promise of self-assembling devices. Indeed there is a great deal of science fiction based on nanotechnology (e.g., "Prey" by Michael Crichton, or "The Diamond Age" by Neal Stephenson). Unfortunately, it's still pretty much science fiction. Let's hope that changes in the next 50 years. Alien technology? That's an insult to the many human scientists and engineers who have devoted their careers to developing this technology. Get real!

You can find lots of great info on nanotechnology on the web, which really just means the engineering of devices and structures whose size are 100 nanometers or less. It's a very broad term. It's definitely not alien technology, and is mostly an outgrowth of the semiconductor industry who have been making transistors with smaller and smaller dimensions over the last 40 years or so. There's a law, called "Moore's Law" that states that technology will be able to double the number of transistors in a given chip every 18 months. So far that "law" has been holding true for more than two decades, but they are approaching a barrier soon, and further improvement will require engineering at the scale molecules and atoms, which is where nanotechnology comes in. Nanotechnology can be useful for a lot more than microelectronics, though. That's only the beginning. Being able to engineer devices on that scale allows us to do some very remarkable things and to take advantage of certain physical effects that occur only at quantum (atomic) scales. For example, a filter made of carbon nanotubes could be used to create fresh water from saltwater, by passing the water through the tiny tubes. Normally, using classical mechanical laws, water would pass through these tubes with great resistance because they are so small, but due to quantum mechanical effects, the resistance is more than 100 times lower, making it a very efficient filter, and dramatically lowering the cost of desalinizing (removing the salt from) water. Here's a good starting place to learn about Nanotechnology: http://en.wikipedia.org/wiki/Nanotechnology

its smaaalllll very smalll!!