I think you've got two options: Have a cofounder, or have a counsel. A counsel would be people you greatly admire that are in your corner during the really ugly, dismal, brutal alone knock-down kicked-in-the-teeth "where the hell do I go from here?" moments. And there'll be plenty of them.

I know not everyone is a Tim Ferriss fan here, but this particular blog post is brilliant:

http://www.fourhourworkweek.com/blog/2008/10/03/harnessing-e...

Having a counsel of people you can go to is a viable option instead of a cofounder in my opinion, but it's hard to put said counsel together without blazing away in business for a few years.