HP announced in April 2008 that they had developed a switching memristor. This is supposedly an electronic device that falls under the fourth, previously unknown and now debated, fundamental circuit element. In 1971 a link between charge and flux was missing from the four fundamental electromagnetic quantities (charge, voltage, current, and magnetic flux), and the element that linked them was named “memristor”, but was not developed.
It is an interesting technology due to the fact that it could create non-volitile memory that is both cheap and many can fit in a tiny space. Part of the discovery is due to the new capabilities with regard to nano-technology. The uses are not fully known, but it might never see the light of day due to the domination of the transistor and other non-volatile memory that already exists.
Basically a memristor is fundamental a charge-dependent resistance element. This means that the magnetic flux over the element is a function of the amount of charge that has passed through it, simply changes resistance as it is “(dis)charged”. However, don’t take my word for it, as I understand the subject, but have done no research. Instead take a look at some other reports: