Why did Facebook pay $1 billion
? You'll have to ask Mark Zuckerberg. But there's no question the photo-sharing program is a wonderful way for shutterbugs to showcase their work -- and snaps from Denver demonstrate the creativity boasted by so many of our friends and neighbors. Check out twenty eye-popping examples below -- and if you've downloaded the app, be sure to click on the links to see more of each photog's incredible images.