Calling just to chat can be flop sweat-inducing in men and women; broach it like "I've really enjoyed emailing with you; the thought of phone conversations makes me a little nervous -- I always worry that I babble or that I'll run out of things to say, but I'd like to try it. I feel like you'd be even more funny/thoughtful/clever on the phone. You want to try to communicate a bit the old-fashioned way?"
You can leave out "And I really want to see if you're a mouth-breather so I can go back to wasting my time on network TV if you are."