Apart from the brilliant riposte given by a Democratic Congressman from Massachusetts to a ill-informed town hall protester with a reality tunnel so narrow the light of day seldom enters through, many people are confusing the "public option" - namely setting up a government run enterprise to compete against private insurance companies to cover uninsured Americans - with "nationalized" medicine directly owned and administered by a government agency much like Medicare Australia or the UK National Health Service.
What many people aren't aware of is that what Mr. Obama terms the "public option" has been tried and works rather successfully in Australia under the guise of Medibank Private, the government-owned public health insurer. Originally a not-for-profit entity, it was recently incorporated and thus required to pay tax on its earnings; therefore wholly funding itself (through users subscribing to its service and reinvesting profits into the business) and contributing toward the upkeep of the public health system through the 10% GST (as well as the other taxes it will now be required to pay as an incorporated entity.)
As a beneficiary of Medibank Private* rather than one of the myriad other private insurers on the Australian market, it works rather well if you can afford to pay, as well as taking up the 30% government rebate and the waiver of the Medicare levy surcharge if one earns over AU$73,000. Of course people still point to the public health system as inherently inefficient despite the private sector attempting "relieving the burden" on it. In my view, pundits from both sides should be looking at the other side of the coin: in reality Australians that are covered with private health insurance experience little to no waiting times for care in the private sector - which is the only option most people in the US have. Although the fallacious "USPS does well against privately run mail carriers" argument may fall through, an extensional and largely functional example could prove more compelling for policymakers and those who matter the most in this debate - the 46,000,000 uninsured.
*in July 2007 I underwent a hernia operation and could pick my doctor, time of surgery and hospital I was admitted to, all with a private room via my coverage (at the time) with Medibank Private.