Via Bike Portland,
A really amusing video that likens forgetting bike lights to forgetting to wear your pants.
Strategies for Getting Around Without Bike Lights (or Pants) from BICYCLE TRANSPORTATION ALLIANCE on Vimeo.
I think that the analogy of how silly forgetting either would be isn't made quite explicit enough for this to be a general public PSA, but it's pretty darn funny.
Kudos to the guy who was brave enough to model his tightie whities!