A simple class task that can be completed over a few lessons.
Each group is given a product - the more silly it is, the more fun they have. For example some products I gave were 'water bottles', 'stationery' and 'toilet paper'. However, they cannot tell other groups what their product is...that must be successfully 'revealed' in their advertisement.
I record each of them and play them to the class and they complete an evaluation of their efforts.
I have done it with Year 8 and Year 10 and it was very well received.