Silent debate:
Simply put a debatable question or statement in the middle of a large piece of paper, and students discuss in silence by writing their answers and questions on the paper. This allows for the whole class to contribute at the same time, and allows quieter students to have ether voice heard. I use different colour pens, so I can check who is writing what. It works with 2-4 minutes per questions, and students rotate round the room (I usually have 6 different questions).
Football pitch comparison method:
This is not an easy one to explain, but really effective for developing a comparison between two concepts/texts/objects, and looking at shades of grey. Your two 'things' belong to different teams, students then have to discuss which 'team' your comparison points belong to. The closer to one goal, the more in common they have with that team, in the middle of the pitch is a complete similarity (50/50 - as much in common with one team as the other). See example below.
Concept maps:
Simply write key words and key concepts on a large piece of paper. Students discuss, connect and explain how these concepts are connected. This allows you to check whether they have understood or know the key concepts, and allows student to discuss and make more creative links. It lead to more developed understanding of the concepts.
Below are a few slides, with some examples from my lessons.
Please use the 'pop out' icon in the top right of the window below, to view the presentation in a larger, separate window.