Olafur Eliasson. So hot right now. Not only does this bigshot Danish artist have a major retrospective exhibition spanning both New York's MoMA and PS1 Contemporary Art Center, he's built four huge, functional waterfalls along the shores of Brooklyn, Manhattan, and Governor's Island. We've been hearing buzz about this project all year, but today's the day: water started flowing this morning at 9 a.m. and will pour on through mid-October.

And we thought Chris Burden's Rockefeller Center 65-foot Erector-set skyscraper was cool. Actually, it sort of is, but what can we say--somehow, erecting a fake skyscraper in New York isn't quite as gripping as building real waterfalls.

Photo: Rochelle Steiner, courtesy of Public Art Fund