The population of the tiny Irish village of Moneygall will swell to several times its size when the President and his sizeable entourage touch down today.
For the 300 inhabitants of this Irish village, the visit is nothing short of a miracle. "It's unbelievable," said Ollie Hayes, landlord of one of Moneygall's two pubs. "Everyone is just in good humour – good crack, laughing and making fun about it, all positive. We're making sure we'll get the whole thing right – it'll be a day to remember. The village will be in mint condition."
Most of the residents took to the streets yesterday to have a last look around before a security lockdown is put in place.
Then this afternoon President Obama, whose great-great-great-grandfather Fulmouth Kearney came from the Co Offaly village before emigrating to America in 1850, is due to make his arrival by helicopter.
The local Church of Ireland Canon, Stephen Neill, enthused: "The mood is absolutely electric; there's huge anticipation and excitement. The people have been given a real boost to their spirits – it's something to celebrate in what have been very dark times in our country economically."
Some 3,500 litres of paint, donated by an enterprising manufacturer, have been used to paint almost everything in the village that doesn't move. Every house has been re-done along with the school and the two churches, Catholic and Protestant.
There was, said the Canon, no shortage of volunteers, adding: "It has really brought people together with community spirit."
It has also produced some entrepreneurial spirit, with a number of gift shops suddenly materialising as Moneygall tries, with some cheerfully kitsch products, to extract commercial advantage from its world-famous visitor.
There are items featuring Obama and shamrocks and Obama and Guinness, while the local chip van will be offering Obama burgers. A new website is offering an array of T-shirts, priced at €15 each, with slogans such as "What's the craic Barack?"
A tongue-in-cheek song meanwhile proclaims: "O'Leary, O'Reilly, O'Hare and O'Hara, there's no one as Irish as Barack Obama. From the old Blarney stone to the green hills of Tara there's no one as Irish as Barack Obama."
Mr Hayes has been practising pulling what he describes as "the most important pint I'll ever pour", which he hopes to serve to the US President. The bar features a large bust of the President and many other bits and pieces associated with him.
Ireland loves welcoming American presidents, and especially remembers trips from Bill Clinton and, most of all, John F Kennedy.
But this will be the biggest thing ever to hit Moneygall, and Ollie Hayes hopes it will bring lasting benefits to a village which, until now, has been off the beaten track.
"We hope we get good responses," he said yesterday. "Oh please God aye."