ROBERT GIBBS STEPS DOWN...

Washington (CNN) -- White House Press Secretary Robert Gibbs says it's been a "remarkable privilege" to be President Barack Obama's top spokesman, "even when you wake up at 4 and pick up the paper and groan."

"I would not trade the worst days here for many of the best days at another job," Gibbs told reporters Wednesday, after announcing his departure from the White House. But he said he wants to "step back a little bit and recharge some" after four years of campaigning and a hard-fought first half of the Obama administration -- "probably the busiest years that Washington and the White House have seen in a couple of decades."

Gibbs said he will leave the podium after the upcoming State of the Union address -- but will remain in the Washington area as a pundit, supporting White House positions on cable television and in speeches.

"It's a remarkable privilege. It is in may ways the opportunity of a lifetime," he told reporters at the daily White House briefing. But he added, "We've been going at this pace for four years."

No decision has been made about his replacement, he said.

In a written statement, Obama hailed Gibbs as "a close friend, one of my closest advisers and an effective advocate from the podium." But he said it was "natural" for his longtime aide "to want to step back, reflect and retool."

Gibbs had an easy, joking relationship with the press, and brought the briefing room down in laughter when he mocked Sarah Palin by writing notes on his hand, shortly after the former Alaska governor was revealed to have done the same for a question-and-answer session.

He also took a journalist's cell phone away when it rang during a briefing, and tried to confiscate a second one.

And he wore a Canadian hockey jersey at the briefing podium in March when he lost a Winter Olympics bet with Canadian Prime Minister Stephen Harper's spokesman.

Gibbs joked his attire "does signal casual Friday" at the White House after Canada beat the United States to win the hockey gold medal.

He turned around to show his last name and the No. 39 on the back of the red-and-white jersey featuring an iconic maple leaf -- then took the jersey off to reveal a Team USA jersey underneath, which he wore through the briefing.

Gibbs was Obama's spokesman during the 2008 presidential campaign, having joined the future president's team when Obama ran for U.S. Senate in 2004.

The Alabama-born Gibbs is a vocal supporter of Auburn University who shares Obama's enthusiasm for sports.