All the best (and fun) scaling issues is best solved by hacking. Is there really any proper decent methods out there that can actually take a company from 5 users a day to 5 billion without any problems at all? I'm aware that you could perhaps "foresee" it, and get a big data-center, and lots of hardware solutions -- but is this really the solution that's called an 'out of the box' solution?

Sounds like when Google gets a problem, they create something to fix that, which is pretty damn cool in my opinion.