30. Divide larger groups.
Introductions in the classroom or at a meeting. Especially poignant the older the group is.
Give your participants a few minutes to imagine what life will be like on Planet Earth in 100 years, and what message they would put in a time capsule to be opened by their ancestors then. When you conduct introductions, ask each participant to share their message and why they chose it.
No debriefing is necessary unless the exercise involves your topic in some way.