Okay, here's what's going to happen. Starting today, I will post a link in comments on an almost-daily basis.
From that link, you will be able to download a secret fifteen-year-old surprise. There will be at least 23 surprises between now and October 8.
Each download link will be good for seven days. After that, it will expire. So ... if anything from fifteen years ago interests you, you should bookmark this post and check back every day or so.