Online. Though I've got plenty of people I connect with in such a fashion IRL, it's easier to do so online.
Many of my 'best friends' are people I talk to online.
And, in mediums such as Facebook, I control what I put out into the world, rather than being bound by the social context of the situation. It's my domain with my unadulterated thoughts, and people respond as they are going to respond--sharing in my domain, if they 'get' me.
When you talk online, it is more about ideas and thoughts than about the current situation or thing that you're experiencing. You're not at some bar looking for no-frills, shallow conversation; you're there explicitly to share your ideas.