I think it depends a lot on the relative standing between you and the company.

There are a large number of startups and small businesses where I could get a job simply by saying "Hey, I'm interested", walking in, and having a 15-minute chat with the founder. I would probably not want to work for most of them, though, because it's quite boring being the smartest guy in the room.

However, the number of people who could get hired at Google or Facebook without an interview is probably in the dozens to low hundreds, worldwide. And many of them probably aren't interested, because they've got their F-you money, or they have a nice tenured research position somewhere where they can do whatever they want.