HP have implemented some decades-old theory and built resistors that have modifiable impedance. Which has some interesting implications, especially for persistent memory design. As an aside, the rather sparse Wikipedia entry says they can also be termed ‘flux capacitors’ – either a hoax edit, or really lame. Not that ‘memristor’ sounds much better.
Since I wrote this post, the Wikipedia article has been expanded and no longer mentions flux-capacitors. I suppose I should applaud the self-correcting power of the Interweb, or something.