Its called a rave, and they are the kind of things that are generally worn at a rave, see...
http://www.fantazia.org.uk/Scene/ravewear_history.htm
The countdown at slammin vinyl (a rave) on new years eve last year..
http://www.youtube.com/watch?v=TDWNcA1r5XI
EDIT: klutch beat me to it, damn you!