Arcade Fire’s performance at Coachella, which apparently has let people in awe since, was especially memorable because of their ‘Wake up’ final: 2,000 LED enhanced beach balls were launched above the crowd, part of a visual project developed by Chris Milk, who had already worked with the band on the ‘Wilderness Downtown’ idea.
This guy has all figured out the technology inside these balls if you are interested:
http://www.idreamincode.com/2011/04/17/arcade-fire-glowing-ball-drop/
Sure, it was a nice idea and very pretty to see these giant balls changing colors at the same time, flying all over the place (I just saw the video), but one of the people who have managed to catch one of these balls, is now shamefully selling it on eBay for the crazy amount of $999!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=150593760314#ht_1206wt_901
The official video of the performance has been removed from YouTube, but you can watch this one: