Alternate Title: "This Blog Entry is Both About History and Not About History - You Have to Read it To Find Out"
When did work start on quantum computing? Well, that is a difficult question to ask. It was a topic debated by all of the great classical physis - Einstein and Bohr. Einstein did not believe in quantum physics, Bohr did. They actually argued/discussed the topic many times at great length until Einstein's death in the 1950s.
Some believe that the first "real" work began in the 1960's when Richard Feynman proposes theories of quantumelectrodynamics. It wasn't until 1982 did Feynman actually came up with the idea of quantum computing - combining the world of quantum physics with that of computing. (In addition to the links above Centre for Quantum Computation (CQC) has some interesting information about the history as well.
Things really became interesting when around 1994 Peter Shor proposed what is now known as Shor's Algorithm. This algorithm runs in polynomial time and can be used for factoring large numbers on a quantum computer. (Hence, breaking traditional encryption algorithms). Which is why many believe that when quantum computing becomes a reality - the field of computers will change significantly.
Well, that is my extremely brief history - well, the parts I think are interesting and significant anyway. Thanks for stopping by and reading my blog!