By Kevin Anderson BBC News Online correspondent in New York

Gerald Nihan was sceptical of the Tribute of Light, two banks of powerful lights projecting into the night sky as a temporary memorial to the victims of the 11 September attacks.

"I thought it would be like a ghost ship that it would be too sad to see," he said.

But instead he found the lights to be a deeply moving, spiritual memorial to the nearly 3,000 people who died in the attacks.

Thousands of people gathered Monday in lower Manhattan to see the lights, six months after the attacks the toppled the towers and have left some 2,800 people still missing.

Courageous comeback

Mr Nihan has lived all of his life in Manhattan, and he was deeply affected by the attacks.

For many, it is still too early to think about a permanent replacement for the World Trade Center

He saw the flames as the second plane hit the south tower. "It was the worst thing that has happened in my life. I felt crippled for months," he said, adding, "I would have given anything to pull one more person out alive."

He thought the attacks would cast a pall over the city for years, but he said the city has made an amazing come back in a very short time.

And he credits the leadership of former Mayor Rudy Giuliani, New York Governor George Pataki and President George W Bush. "They showed us the courage to get beyond our sorrow," he said.

Newlyweds reflect

On the other side of Ground Zero, Dave Lambert pointed out to his wife of five months, Beth, where his office was in the old Banker's Trust building, a building that still bears a long gash down one side from debris from the falling towers.

Six months after the attacks, they still remember the morning clearly.

It was three weeks before they were married, and Dave often called Beth in the mornings so she wasn't surprised to when he rang.

The lights are supposed to be visible for a mile up in the night sky

"I didn't think it was anything but an 'I love you' call," she said. Instead, he told her to turn on the news, as he watched debris fall from the World Trade Centre towers.

After that phone call, he couldn't reach her for almost three hours, and she didn't know if he had been safely evacuated.

Fortunately, he was, and although they knew several people who worked in the World Trade Centre, all of their friends survived.

But it still affects him. "For me, I take it one day at a time. Some days, I go on with my normal routine, and other days, I think about it and replay it in my mind," he said.

He thought the Tribute in Light could help people still struggling to cope with the loss of love ones or simply trying to come to grips with the destruction they witnessed.

'Too early'

The Tribute of Light is meant to be a temporary memorial. It will shine for the next 32 nights from dusk until 11 pm.

Little concrete progress has been made on plans for a permanent memorial apart from laying out a process for memorial planning.

It is still too painful to be asking if they prefer glass or granite while remains are still being recovered

Dianne Baumert-Moyik, victims' association

Beth Lambert believes that the city and the victims' families will need more time and distance before making decisions about a permanent memorial.

And indeed that is what some groups who represent families of the victims are saying.

"It is still too painful to be asking if they prefer glass or granite while remains are still being recovered," said Dianne Baumert-Moyik, spokeswoman for the Widows' and Families' Victims Association.

They are still focussed on recovery and hope more remains will be found as the excavation of the south tower continues.

No tall towers

Rich Dallas rushed from 7 World Trade Centre for a ferry after the attacks. The bank he works for decided early to move their operations

The beams of light remind, commemorate and comfort

Three or four minutes after leaving Manhattan on a ferry, he watched as the first tower collapsed. His building collapsed later that day at 1728, he remembers the time exactly.

He remembers much about the day. "It's hard to believe that it's been six months already," he said.

When it comes to talk of a permanent memorial, Mr Dallas is certain of one thing. Rebuilding the 110-story towers is out of the question.

He doesn't believe that anyone in New York would want to work in them, and he said, "It would just entice them," referring to the prospect that it might lead to additional terrorist attacks.