I'm not sure what to call the circuit involving the chain of uninsulated Brainiacs in this clip. See 2:13-4:00.
The segment from 4:00-4:53 is a nice example of a series circuit!
UPDATE: Commenters and NCNAAPT/PTSOS list responders have identified this as a resistance ladder or R-2R network. I love having access to the brainiacs of cyberspace!