I've noticed that once the wheels of conversation have been greased (via beer and a few presentations), during the interval people really seem to mingle and chat. To my mind this is the golden 10-15 minutes of the hacker news meetup.

Here's the rub, there's usually only a 10-15 minute break. I'd argue that these conversation are largely the point of the whole meetup. Dmitris' introduction quiz was a good idea, and I think worked well. However ultimately people need time to develop and evolve a conversation.

My suggestion would be to cut one of the talks in the second half and let the mid-session break stretch on for 30 minutes .