The place to be (Milan)

I moved to Milan 3 months ago but I'm afraid to say I've been so busy with work I've hardly gone exploring or made any friends. I was wondering - is there a good bar or pub where people go to meet people?

When I lived in Hiroshima there was this great place where anyone new to the city always ended up visiting, and it was easy to just end up talking to someone new. I'd love to find a place like that!