Jeffrey Talajic discusses how to find a technical cofounder. In short, go to the relevant networking events, talk to people, discuss your project, let them self-select, and bring them on slowly while testing out the relationship. Oh, and be picky about who you select.
Decent advice, apart from one thing: I believe that if you've started your business already, it's probably too late to find a technical cofounder for this one (though you can find a good CTO-for-hire). But you can find a tech cofounder for your next business.
You shouldn't start a business with someone you've just met. Let the relationship evolve, grow, and solidify, and then consider starting a business with them.