Lee Brimelow, Flash Evangelist/master spy, has launched a global hunt for free copies of CS4. He's going to be leaving a copy of CS4 everywhere he travels and posting video clues to help find it on his blog.
http://theflashblog.com/?p=712
The first one has been put out already and according to Lee's Twitter feed someone went last night at midnight to look for it but turned back at the trailhead.
Lee will be at FITC Amsterdam in a few weeks so I'd suggest watching his blog if you're going to be in Amsterdam from the 22nd - 24th.