I spent the first part of the week in New York. As I've said before, it's not the USA. It's an exciting world of its own and central to the world as we know it.

I stay in a hotel just around the corner from Trump Tower and POTUS was in residence all week because the United Nations is in session and he has been glad-handing world leaders from everywhere other than Australia.

"You mean 'bad' handing'," grimaces Louise at the thought of his grip on things, including hands.

Our Prime Minister didn't make it, but the Foreign Minister did. But that's all a well-lit blind alley.

America has always reinvented itself and it's doing it again. The international reporting we get on Donald Trump doesn't really matter here.

The hedge fund guys, as they're called, and entrepreneurs of all kinds, are upbeat in the hustle and bustle of NY NY. The US economy is growing at 3 per cent, nearly twice as fast as ours.

Tuesday night was the gala opening of the New York Philharmonic Orchestra season and I'm delighted to be on the board.

My guest for the night was the wonderful John Berry. Some readers will fondly remember John as the most recent American ambassador to Australia. He is an outstanding individual, and in fact President Trump is yet to find a replacement nearly a year after he left.

The gala was couple's night and a grand dress-up occasion. John came with his partner Curtis. Yes, this is a same-sex marriage and it works.

The orchestra was brilliant, as were the canap??s, which were followed by a dinner in the tent at the Lincoln Centre.

"They have a tent at Lincoln Centre?" asks Louise. Yep. It's even got its own Facebook page.

But a trip to New York always puts one under pressure, especially if you're a poor boy from the Victorian alps who wants to be seen as a man of the world.

"You mean a person of the world," says Louise. That's true and that's the correct lingo. You don't want to look like you don't know the rules around here.

And one of the things you have to get right is tipping. The key to that is handing over the right amount. You never want to get that stare from a NY cab driver, if you hand over 10 per cent in coins. It's 15 per cent minimum and in the folding stuff.

So without avoiding eye contact I warily fumble around with a handful of notes that are all the same size and the same colour. You certainly don't want to want to peel off what you think is $US15 and find out on the curbside that you've just handed over $US1500.

I made that mistake in a downtown restaurant not so long ago. The waiter immediately tore off the apron and left the building waving the cash above his head.

Never under tip. They will talk about you and they won't let you in ever again. So, in my panic-stricken form as a cool operator from the antipodes who is very keen to return, I always tip high and often. I can put on a black tie and hold my own at the Philharmonic Gala, but at tipping I'm rubbish, as the English would say.

It was much easier to work out who to tip on our recent trip to St Petersburg. That bulge from the shoulder holster made it all pretty clear.

Louise and I left New York on Wednesday and headed for Prague, which is where I am now. This wonderful, exciting city rebuilding itself from the difficult history of the 20th century.

Part of its rebuilding is engaging with the world through sport, and later this week it is hosting the inaugural Laver Cup - an international celebration of the extraordinary career of Rod Laver.

It was Roger Federer's idea and it is a short form of tennis over three days. They tell me that if you look around the outskirts of the crowd hard enough, you'll spy Bill Gates, Richard Branson and a group of people who understand how a strong global economy is supported by international sporting and cultural engagement.

I'm proud that Australia is playing its part in the new organisation that has pulled all this together.

The Laver Cup will be an annual event and is scheduled for North America next year. I'm sure it will come to Sydney at some point.

Tennis Australia is one of the promoters, together with the American Tennis Association and representatives from Wimbledon.

No pressure here. Just a great city, one of the prettiest that I've seen, and a bunch of entrepreneurial Australians who know what "c'mon Aussie, c'mon" really means.