Robotics people sometimes are asked to be a Robot Show presenter. They look for ideas of what might get people interested in robotics. Here is an idea of a great show built using Lego robots and other contraptions, called the Cooperative Cybernetic Crate Contraption, by the SMART group, but one can be inventive and build something similar, probably less spectacular, using regular robots and contraptions. This idea sparked into a Lego Rube Goldberg Machine and at the BrickFest 2005 a large number of Great Ball Contraption modules were put together into a big setup. This was a huge attraction, so they followed in the next years with even larger setups. Watch the videos so you can get some inspiration.
https://www.youtube.com/watch?v=gFZ7x4s1eHo