There is a group behind the whole thing called the National Informal Science Education. From their site:
The NISE Net is a national community of researchers and informal science educators dedicated to fostering public awareness, engagement, and understanding of nanoscale science, engineering, and technology.
No one at the event was from NISE. A presenter did mention that they wanted to go out and educate the public on nanotech, and garner feedback. She intimated that it was a way to bring something to market with support of the public. Cynically, I smelled a brilliant PR campaign behind it. I'll follow for a while and let you know if they gain my trust.
An element at the nano scale takes on different physical properties from its larger version. The FDA does not distinguish. For example, aluminum. We all use it, it's safe, but it behaves very differently at nano scale. Story is a pile of it burst into flames on a humid day. Un-extinguishable, it burned through a table, the floor, and left a divot int he concrete sub-floor.
We use nanoparticles in our sunscreens. Th same ingredient as in the old, white zinc oxide creams of yesteryear have been replaced with smaller nano versions. They are transparent at this scale, thus disappearing on your skin. But we're not sure if the properties of the smaller version is safe. Testing is not required. Caveat emptor.
Igniting nanoparticles with weak laser has wide variety of applications