Networking & meetups are great, as mentioned. I am also seeing a lot of people on good tech mailing lists start to reach out as well for co-founders. Groups li

Networking & meetups are great, as mentioned. I am also seeing a lot of people on good tech mailing lists start to reach out as well for co-founders. Groups like NY Tech Meetup (http://www.meetup.com/ny-tech/ http://www.meetup.com/ny-tech/), SF New Tech (http://www.meetup.com/sfnewtech/ http://www.meetup.com/sfnewtech/), various regional founders groups on facebook are all places I've seen people connecting to talk about working together on startups. I don't know how useful it is, but I've also heard mention of Founder Dating (and there are regional meetups for those as well): http://founderdating.com/ http://founderdating.com/ Good luck!