Nanotechnology can potentially cure disease or lift a person into space, but on to more important stuff.  Clean windows.  Scientists from Israel have been working on a coating that is self-cleaning.  Using peptides which are short pieces of protein, coatings could be made on a whole bunch of different kinds of things.  So what makes this stuff so neat?  By carefully designing the peptides, scientists could make them very hydrophobic, meaning that they don’t like water.  If you can keep the water off the surface you can also keep the dirt.  So when it rains everything comes washing off and what is left is nice and clean.  Same kind of peptide coating is also useful for solar cells and even rechargeable batteries.