Looking for bars/ideas that bars use to get patrons to MINGLE?

A lot of bars either consist of cliques of friends standing around, or blast dance music.

I’m looking for a list of bars that offer particular games/activities that encourage people to mix and mingle. For instance, I heard about a bar that has telephones at each table – people call other tables because it’s fun and goofy, and end up interacting with strangers. Another one that I’ve seen simply seats everyone at a table with strangers, rather than together.

What other ideas have people seen at bars that encourage this type of interaction with strangers?