Gibbs is leaving the White House after two years as press secretary and one of the president's closest advisers. He'll take some time off to give paid speeches before eventually joining Obama's reelection campaign full time.
Gibbs, 39, has worked for Obama since his 2004 Senate campaign. He was with Obama in Boston during the Democratic convention that year when Obama delivered the keynote address that catapulted him into the national spotlight.
Obama said Friday that it wasn't what he would say in that speech that caused the most concern that night: it was which tie he would wear.
"Then somebody turned and said 'You know what, what about Gibbs' tie? That might look good'," Obama said. "And frankly Robert didn't want to give it up."
Gibbs eventually did hand over the blue tie he was wearing, Obama said. On Friday, Obama gave Gibbs that tie back, framed in a glass case, along with a photo of Obama from the convention.
Obama lauded Gibbs as an "extraordinary" press secretary and a great friend. He joked that Gibbs' departure was not the biggest of the day, a reference to Egyptian President Hosni Mubarak's resignation earlier Friday.
As he ended his final daily briefing with reporters, Gibbs said it was "a tremendous honor and privilege" to serve at the White House. He said he's now looking forward to spending more time with his young son Ethan.
The new press secretary, Jay Carney, starts Monday. He is a former journalist who has spent the last two years as Vice President Joe Biden's communications director.