In this fast changing environment, conference are also changing faster and adopting new and innovative ways. DISRUPT HR Conference (http://disrupthr.co/) has this interesting format of talks delivered within 5 minutes.
This kind of setup require speakers to reinvent their talks/speeches/presentations in a highly agile manner to pass their message to the audience.
Here is a sample video for a talk delivered in 5 min. Further talks can be accessed here http://disrupthr.co/talks/.