The Scouts each bring with them a hobby which they can talk about for a few minutes
We used this for cubs too.
The Scouts need to bring with them some thing to show or demonstrate the hobby
Asked boys to explain what their hobby was, how long they'd being do their hobby, what equipment, facilities they needed, if it was a group hobby, did it involve a team, safety gear, what were the rules etc
Boys presented this info to their peers - we split a pack of 24 into 2 groups of 12 and it took about 5 mins per child. Will take longer if group is bigger
Note - cubs collect badge only applies if a cub brings in a collection to share