A Pied Piper by lantern, fireworks, labyrinth walks and an attempt to set a Guinness world record for oak-tree planting overnight are some of the events being held in Galway and Mayo to mark the century's turn.
Come more hail, lightning, lashing rain or snow, the people of the Mayo village of Balla are determined to make their mark. One hundred volunteers with shovels are preparing to plant 20 oak trees each - one tree for each of the past 2,000 years - from the stroke of midnight on.
The project is also very practical - during the severe storms around Christmas last year, Balla's ancient oak forest was devastated.
It was when the community was debating the tree-replacement that a retired garda sergeant, Mr Stephen Clancy, came up with the idea, set up a committee and even got an official clock recognised by the Guinness recorders - it depends on a radio control signal transmitted from the National Physical Laboratory in Rugby, England.
He knows it isn't the best time of year for planting, but if even some of these saplings survive, the woodland will have been restored.
Balla's Dawn Oak 2000 project will be dedicated to 2,000 sponsors worldwide, whose names will be kept for the duration of the new wood's life - perhaps to the next millennium.
Two ordained brothers were behind two labyrinth walks - in Furbo, Co Galway, and Shrule, Co Mayo. "People want something significant, not just fireworks," says Father Denis Crosby of Furbo. Labyrinths date from the time of the Crusades and were built as indulgences for pilgrims who could not go to Jerusalem for safety reasons.
The oldest known labyrinth pattern in the State comes from a stone inscription in Hollywood, Co Wicklow.
The most famous geometrical route can be seen at Chartres Cathedral in France.
Father Crosby's parish swung behind the idea, and there was a similarly supportive spirit in Shrule, where his brother, Father Mike, is priest. Furbo's sandstone route, or meditation path, has attracted many visitors. Mayo will host various "last light" ceremonies and in Ballina they are hoping that UN High Commissioner for Human Rights, Mrs Mary Robinson, a native of the town, might show up.
The ceremonies begin outside Ballina post office at 3 p.m., finishing at 4.30 p.m. with music from the Mayo Choir and local artists, and with a poem specially commissioned by the town's millennium committee.
About 100 children with lanterns will participate and people have been asked to bring their millennium candles.
In Galway city, where the main pubs will be closed and taxi and hackney companies are levying a once-off £5 increase in fares for the night, the festivities begin early in the afternoon of New Year's Eve. Galway Corporation's Millennium Committee has organised events for at Eyre Square, at the Black Box theatre, and on the streets in between, involving De Danann and the street theatre group, Macnas.
The events begin at 1.30 p.m. with the raising of a millennium flag and this will be followed at 2 p.m. with entertainment provided by "death-defying" Johnny Massacre, Pippa the Clown, the Renmore Pantomime Society, and others, with music by the Galway Early Music Society and the Cor na Mara choir.
At 3.15 p.m. there will be a free live concert with De Danann, with Eleanor Shanley as guest vocalist and legendary box-man, Jackie Daly.
At 4.28 p.m., the official sunset on the past 1,000 years, the Mayor of Galway, Alderman Declan McDonnell, and religious leaders will light a giant millennium candle made by Mike Regan and Pete Sammon.
The Pied Piper then takes over 15 minutes later, when some 150 children bearing lanterns will "woo" the dignitaries away.
Macnas, who will be trilocating on the night that is in it in Galway, Merrion Square, Dublin, and Times Square, New York, have roped in school and community groups for the procession of light.
The route finishes at the Black Box Theatre just in time for a fireworks display by the World Famous Fireworkers at 5.30 p.m.
Later that evening, the Galway Town Hall Theatre hosts a millennium concert which promises diversity, colour and mayhem - including a 10-minute countdown to 2000, starting with a nine-minute suite commissioned by Galway Corporation and composed by Martin O'Connor, Carl Hession and Brendan O'Regan, with a backing band.
Musicians from city and county will take the stage and the event will be presented by Derbhile Ni Churraighin from TG4 and directed by Mary McPartlan.
The show begins at 10 p.m. and ends at 12.45 a.m. on New Year's Day with a party and a champagne bar.
In south Connemara, the "turn" has already been marked by participants with Muintearas, the Gaeltacht education project. On Saturday, December 18th, a 28-ft gleoiteoig beag, Naomh Chiarain left Maimim Quay for Inis Oirr.
Making the "last sail of the century", the gleoiteoig was loaded with turf for the island's elderly, distributed by a mini-crew of pupils from Inis Oirr National School.