Yeah, wifi has definitely put a damper on the traditional coffee shop vibe. Some shops are worse than others, though.

My advice is: find a busy shop with regular customers. Make friends with the baristas, and hang out near the bar when it's busy. Talk to the baristas - most will welcome this (I'm a former barista. Conversation with customers makes the day go by faster. If the baristas don't want to talk, find another shop.) You will inevitably be pulled into conversations with other customers by hanging out at the bar. It's like a conveyor belt of ever changing personalities. Eventually, people will ask you to socialize outside of the coffee shop. Success.

This always works. I've done it a number of times. When I go to a new place and don't know anyone, I find a coffee shop.

also: make sure you go on weekends - people are more willing to relax and talk when it's not during the workweek.