Mayor Michael Bloomberg gave a humble inauguration speech Friday, on the first day of his third term as New York City Mayor.

In an hour-long ceremony held at noon Friday, Bloomberg said he understands his third term is a "special opportunity."

He was initially prohibited from running for a third term. But, in a rare move, he convinced to City Council to change the term limits law. He was then reelected, but only by a narrow margin.

Bloomberg thanked supporters Friday, and pledged to listen and lead over the next four years.

"Conventional wisdom holds that by a third term, mayors run out of energy and ideas," he said. "But we have proved the conventional wisdom wrong time and again, and I promise you, we will do it once more."

During his third term, the mayor announced a management shake-up. He plans to place City Hall deputies in city agencies for three-week periods, in an effort to generate fresh ideas.

Bloomberg also shared the stage with City Comptroller John Liu, who was the first official sworn in at the ceremony. His appointment marks the first time ever an Asian-American has been elected to a citywide office.

Liu is charged with overseeing the city's finances and managing $80 billion in pension funds. He told New Yorkers he's optimistic about the city's financial future.

Bill DeBlasio will also be revamping his office as a public advocate, vowing to champion progressive causes.

"My office will be a place where the voice of the people speaks loudly," he said. "A place that helps organize communities to play a more meaningful role in our city government. A place that unlocks the mystery of government and refuses to stand by when a New Yorker could have been helped, but wasn't."

Meanwhile, on Long Island, Edward Mangano took his oath of office to become the Nassau county's eighth county executive.

Wasting no time, he announced during his inaugural speech that he had officially repealed a controversial home energy tax imposed under his predecessor, Tom Suozzi, and signed an executive order to begin the process of fixing Nassau's "flawed assessment system."