We will do a coding kata: The participants are split into one or more discussion- and developer-rounds. A pair of programmers solve a small problem in test driven development. The audience can see the code and discuss it. Every few minutes, a developer joins the audience and one of the audience becomes a developer. A moderator supports the group and fosters discussions. As each individual gives input in an open, constructive discussion, there is an exchange of approaches and strategies and team collaboration is improved.
For more information, see: http://codingdojo.org
As not everyone needs a laptop, you are also welcome to join without equipment.
But if possible: A laptop with a browser (preferably Chrome) and maybe even a development environment with test framework and a ready-to-go project with a running dummy unit test already in place.