how about something on food and restaurants? i know it's maybe a bit boring but they generally like to see lots of student speaking time in open classes. food and restaurants gives you a good opportunity to do that by using information gap activities, getting students to practice ordering food etc.

you could do an activity where students create their own menu in groups, then half the students in each group act as 'waiters' and have to take orders from other teams. the other half stay behind and they are the 'customers' and have to give orders to the waiters. then after 5-10 mins they change roles.

eslflow.com has some good stuff on food and restaurants: http://www.eslflow.com/foodrestaurantlessonplans.html

alternatively, there's also some decent stuff there on transportation and technology:
transportation: http://www.eslflow.com/transportationlessons.html

technology: http://www.eslflow.com/technologylessonplans.html

Thanks johnny russian, they have some decent role plays on there--I really like to get my students up and speaking, especially for an open class.

Fishead...what? lol

6 Thinking Hats is a good lesson for high levels that should demo well.  I'd recommend running through it with another class first, though.

http://www.waygook.org/index.php/topic,62874.msg411624.html#msg411624

lukamodric, that's actually a good idea for including the whole class in a debate.  My advanced classes are upwards of 30 students so though I've wanted to hold debates I've always wondered how to make it work best.  Thanks!

Yea, if you were able to upload those I'd really appreciate that!

Here are some of the debate skills I put together.  Some of them need work sheets to go with them but you can quickly make them up.