If you're not already familiar with his work, you should go check out the OLAFUR ELIASSON show "Take your time" at PS1. My favorite piece of his was at the Tate a while ago. Read up on it and his other works at http://www.nytimes.com/2008/04/18/arts/design/18elia.html?scp=1&sq=tate+...
info on the PS1 show is here: http://www.ps1.org/ps1_site/content/view/311/102/
Oliver