Since I'm typically talking about education/technology topics with faculty in workshop scenarios, I think an appropriate introductory activity for a workshop about teaching and learning topics could be asking them to reflect on their past experiences. I think this could be useful since it would allow them to think back to their own learning and get them thinking of the student perspective.
Here are a few ideas:
Another activity that has successfully run in one of my colleagues' workshops in past years about creating a Technology Toolbox involved brainstorming (on post-its) the types of technologies that they were currently using and then having them sort their post-its into categories together. This gave the presenter an idea of where their audience was coming from as they were presenting and also allowed the faculty attendees and presenter to add new tools to their already existing toolbox.