Inge Evertsson of Sweden, vacationing in Berlin, said he likes the idea of Obama as president because it would represent "a new era. America is still the most important country, and the president has much to decide."

Before delivering his speech, Obama told reporters it wouldn't be comparable to famous ones in Berlin by Presidents Kennedy and Reagan because "they were presidents. I am a citizen. But obviously Berlin is representative of the extraordinary success of the post-World War II effort to bring the continent together and to bring the West together and then later to bring the East and the West together. So I think it's a natural place."

He demurred when asked if this was meant as a preview of what sort of president he might be if he were to defeat Republican John McCain in November. "No," he said. "I'm just giving a speech."

But he clearly felt good about his reception — and his trip so far. He invited reporters traveling with him to join him at a restaurant after the speech for an off-the-record gathering, and celebrated with a dry vodka martini with an olive garnish.

A small campaign flap erupted over Obama's decision to cancel a planned short visit to U.S. military bases in Germany. His campaign issued a statement explaining that Obama decided not to visit soldiers at Landstuhl Regional Medical Center because he thought it would be inappropriate to do so as part of a trip funded by the campaign.

McCain's campaign issued a statement criticizing Obama's decision to cancel the visit.

"Barack Obama is wrong. It is never inappropriate to visit our men and women in the military," McCain campaign spokesman Brian Rogers said.

Before leaving Israel for Germany, Obama visited the Western Wall in Jerusalem, accompanied by a rabbi. Although the predawn visit was not advertised, it was widely anticipated, and in the waning moonlight he was heckled by a protester shouting, "Obama, Jerusalem is not for sale!" as other locals who supported Obama tried to drown out the protester's cries.

The Illinois senator had said on Wednesday that he supports making Jerusalem the capital of Israel, but said its ultimate status should be determined by negotiations between Israelis and Palestinians.

At the Wailing Wall, Obama slipped a prayer note between one of the gaps in the stone, as is customary. He placed a hand on the wall and bowed his head.

On the plane from Israel to Germany, Obama told reporters he was wiped out from nearly a week's worth of travel to Iraq, Afghanistan, Jordan, Israel and the West Bank, under stressful conditions, with jet lag, packed schedules and too little rest. Once the plane took off, he said, he was going to sleep.

He described his experience on the trip so far as "moving," speaking in particular about his interactions with U.S. troops, but said one frustration was that when visiting war zones the logistics were too controlled to allow him to talk to the local populations.

Obama will travel to France and England today and Saturday before returning home.