Have students line up according to a specific criteria (e.g., birthdate, number of pets, etc.).
Line-ups can be used to create small groups (count off by 4s) and to promote communication.
Value Line
By making your lineup a value line, you can form heterogeneous groups.
For example, present a topic or issue to the class and ask each student to think about how they feel about it (on a scale of 1 to 100; 1=strongly agree, 100=strongly disagree).
Students line up in rank order from 1 to 100.
You can then form heterogeneous groups by counting off (with 24 students count off by 8 to form 8 groups of 3; those with the same numbers form a team) or pulling one student from the beginning of the line, one from the middle and one from the end.