On Tuesday, the newspaper photos showed travelling companions Ian Paisley and Martin McGuinness holding a gavel on a podium overseeing the New York Stock Exchange trading floor, as if to signal that trading could be begin ...

That event, an hour before trading started, was for cameras. Yesterday was closer to the real deal, as they rang the opening bell at Nasdaq. This time, trading could indeed commence.

Although there was something of a staged feel to that as well - there is no such thing as a trading floor at Nasdaq, America's largest electronic stock exchange.

But neither Mr Paisley nor Mr McGuinness, whose faces were beamed across Times Square on its iconic Nasdaq market site tower, were bothered.

Mr McGuinness didn't object when Jeff Singer, senior vice president and head of Nasdaq International, introduced him as the 'Sein Fine' politician, adding he expected Northern Ireland to become the new Cell-tic Tiger.

"We are here on business, not on politics - what a relief!" Mr Paisley told the assembled media and guests. On the economic conference to take place next year, Dr Paisley said: "I invite you all to come to Northern Ireland in May of this incoming year. We will not have a May Day rally, but we will have a rally to put Ulster on the map. I'm not telling you we are going to release a tiger - ours will be a well-petted dog."

When Mr Paisley was asked in an interview with the Belfast Telegraph how he would respond if the Ancient Order of the Hibernians, the organisers of New York's St Patrick's Day parade, asked him and Mr McGuinness to lead next year's parade - as publisher Niall O'Dowd had recently suggested - he replied: "We are here not on a political crusade. We are here for industry."

Dr Paisley nodded as the Deputy First Minister skillfully dodged the same question.

"These parades are of little concern to us," Mr McGuinness said. " Our focus is about how we can encourage economic investment in the North. That is our top priority. Let's not speculate. Let's deal with the reality."

On Wednesday Mr Paisley met Donald Trump to make a sales pitch to The Apprentice host. Trump originally planned a £1bn golf complex in Scotland, but his plans were rejected by Aberdeenshire Council last week.

Mr Paisley sensed the opportunity, and tried lure Trump away from Scotland to Co Antrim. "I think we are in with a chance," Mr Paisley said. " He showed a real interest in Northern Ireland. He's a man of great wealth, of course, and he has a great opportunity to help us."

But Mr Paisley didn't want to give the impression that he was like an Apprentice entrepreneur, desperate to impress, that Trump meets on his TV show. (Who would ever have the bravery to tell Ian Paisley, "You're Fired!"?). "And we could help him," he continued. "We made that quite clear - we weren't coming with a begging bowl. We were coming to do business."

The "business, not politics" message has been the story of this visit so far. But according to some, there were still glimpses of the old Ian Paisley to be seen.

At a reception at the house of Loretta Brennan Glucksman, the chair of The American Ireland Fund, Dr Paisley's delivered a "blistering" unscripted speech, according to Niall O'Dowd, who was in attendance.

Brennan Glucksman described his speech as "very human. He said I am coming to the end of my life, and that he hoped the Good Lord would give him a few more years to finish this adventure".

Amid such change in Northern Ireland - and of change in Ian Paisley - some things, at least, have remained the same.