I recently gave an "Intro to Groovy" talk for a local CIPS chapter.
It was a special evening: I returned to my alma mater, re-united with old friends, and met enthusiastic students.
I assumed the audience wasn't familiar with Java, and so the narrative was a high-level report of the blossoming ecosystem on the JVM over the past few years, with examples in Groovy. The material is available here.
My thanks to those who attended!