This is an activity that can work very well in a large room with fixed seats (as well as any size group or classroom) Ask each person to take out a half-sheet of paper or give them an index card that they can pass around the room. Ask them to note down something that relates to what you have been doing in the class (be sure to let them know that whatever they write will be shared). It can be something that they do, think or believe or it can be a fact you presented, or it can be a question they want to ask others. Give them 1-2 minutes, then ask them to fold it in half, and pass it along X number of spaces (enough that it is not obvious who wrote what). They then open it, and either add a comment, or a question, or edit it (depends on what you asked them to do). You can vary the number of passes, depending on time; in the end, it has to come back to the person who wrote it. You can then either move on, or ask people to say what they got out of the edits. It has a nice component of quiet writing and reflection, but is also very active, and can link to small group or whole class discussions.