By Steve Holland - Analysis

WASHINGTON (Reuters) - From reluctant CEO to chief U.S. medical adviser, President Barack Obama showed how many hats he wears at a news conference marking his 100th day in office on Wednesday.

Shrugging off critics who say he has taken on too many tasks in his young presidency, Obama said all the issues had landed in his lap at the same time and had to be dealt with simultaneously:

* First off, he was his own U.S. surgeon general, since he has yet to appoint anyone to the job, offering common-sense advice to Americans on how to deal with the threat of swine flu.

"Wash your hands when you shake hands, cover your mouth when you cough. I know it sounds trivial but it makes a huge difference," he said. "If you are sick, stay home. If your child is sick, keep them out of school."

* Obama was the top U.S. human rights advocate, saying the interrogation technique known as waterboarding used during the Bush administration is torture and questioned its use.

Those who insist the techniques gained useful information from terrorism suspects that saved lives fail to answer a core question, he said.

"Which is: could we have gotten that same information without resorting to these techniques? And it doesn't answer the broader question, are we safer as a consequence of having used these techniques?"

* The president, who taught law at the University of Chicago, showed himself to be a bit of a philosophy professor, talking about how he wants to leave behind a legacy of change, that he hopes in 10 or 20 years the next generation will look back and see this was a period of transformation.

"This metaphor has been used before, but the ship of state is an ocean liner. It's not a speedboat," he said.

TOP DEMOCRAT

* Which brings us to the next hat he wore, a comfortable one called top Democrat.

Obama came to the news conference reveling in an approval rating well over 60 percent, his Republican opponents held at bay and their numbers reduced, what with the defection on Tuesday of Senator Arlen Specter to the Democratic side.

"I do think that, to my Republican friends, I want them to realize that me reaching out to them has been genuine. I can't sort of define bipartisanship as simply being willing to accept certain theories of theirs that we tried for eight years and didn't work and the American people voted to change," he said.

* Along those lines, he reprised a familiar role from his Chicago past -- community organizer, trying to get politicians in Washington to come together for the common good at least until lawmakers start seeking re-election in 2010.

"I would like to think that everybody would say, you know what, let's take a time-out on some of the political games, focus our attention for at least this year, and then we can start running for something next year. And that hasn't happened as much as I would have liked," he said.