Memristor

interesting article:
http://www.hpl.hp.com/news/2008/apr-jun/memristor.html

Invented memristor, missed element for electronic schema's.

DRAM element is simple enough, also, but contains two elements instead of one memristor
( http://lwn.net/Articles/250967/ provide a picture with schema, it is transistor + capacitor ) .

Also DRAM requires time for reading and even more for rewriting.
Also capacitors in DRAM leak, when read. Also DRAM requires complex schema for maintaining/reading the state, and there addressing problems.

Also, from the article looks like memristor can store more than one bit of information, that could be read by passing different signal value on IN pin.

Waiting for details and examples of electronic schema from HP.