Eh... founders should always be talking with different, intelligent people and soaking up ideas. If that's what you mean by networking, fine. But I think the networking tptacek refers to is the type that's organized X times/mo. and for the purpose of professional development. It's those ad hoc events where this group is encouraged to co-mingle with this one.

It has its place, but just as useful at times is getting together with a group of peers you trust and exchanging notes. Having a few beers and talking about what challenges you're having, what breakthroughs you've made...

I think the tradtional idea of networking is overemphasized among a lot of startups (and sometimes dangerously so) because it's an abstraction away from the work that keeps them alive. You've got to make sure you keep a watchful eye on your schedule and don't confuse attending X and Y event for Z productivity.