John Archibald Wheeler, high priest of quantum mysteries, suspects that reality exists not because of physical particles but rather because of the act of observing the universe. "Information may not be just what we learn about the world," he says. "It may be what makes the world."
The more I think about it the more I find this view seductive. Although I haven't looked into it, I'm wondering whether this is connected to N. David Mermin's information-theoretical Ithaca interpretation of quantum mechanics (in a few words: "What are real are relationships; correlations, not correlates").
I have to disagree with Wheeler's vision. This is kind of mainstream in some circles in physics (Berkeley's or Heisenberg/Schrodinger's type philosophy). Matter exist independently of our observation. Matter IS real. More there: This is the site of my Ph.D's thesis supervisor. His vision is non-conventional, but it makes sense!