Here is a suggestion for what to say when introducing Marc to an audience:
“Marc Prensky is an internationally acclaimed speaker, writer, consultant, and innovator in the field of education and learning. He offers deep experience and insight into educating today’s youth and into using technology in powerful ways for learning.
Marc has taught at all levels from primary to college, and currently has an 8-year old son who is thriving in the New York City public schools.
You are likely to gain new perspectives and thoughts from listening to Marc, and he asks that you remain open if his ideas challenge some of the perspectives you currently hold. Marc is extremely interested in hearing your questions, concerns and “yes-buts” and in trying to offer helpful suggestions.”
OR, you could simply say
“Marc needs no introduction.”