First off, hats off to everyone involved; The turn-around time for this project sort of blew me away. Everyone was eager to participate, and I think it shows in the final product.
If you want some more details on what each segment represents, you can check out the original thread here: http://www.newgrounds.com/bbs/topic/1383562/1
If you don't feel like reading through all that (lazy asses), each 15 second clip signifies a different year and genre - from the site's origins to present day. There's also an animation being built to go along with this audio featuring some of the flash portal's most prominent artists (http://www.newgrounds.com/bbs/topic/1388594/1).
Now to address the little tiff below...
I've been contributing audio to Newgrounds for over a decade, but the ONLY reason I'm a part of this collab is because I was lucky enough to stumble upon the topic before all the spots were filled. Moral of the story: Be active in the forums!