OP, if you are asking this b/c you are wanting to find a co-founder yourself, I'll offer this advice: be wary of anyone who says (1) they did find a co-founder

OP, if you are asking this b/c you are wanting to find a co-founder yourself, I'll offer this advice: be wary of anyone who says (1) they did find a co-founder through these types of techniques, and (2) who has been with that person for less than one year (or possibly two). I've seen guys who say that they have a startup and then find a co-founder but both are still working full-time on their jobs while trying to get the startup ready part time. That doesn't count to me - if I was looking for a co-founder, I'd want concrete answers from people who had spent 60+ hours a week together for a year or longer.