Making your presentation interactive...
Try using an audience response system to engage the crowd:
1. Download Turningpoint (Mac or PC) free from this website (tutorials are also available on this site)
2. Install Turningpoint
3. Open Turningpoint -- which will automatically launch Powerpoint and then act as a plugin for Powerpoint.
4. Click on the "Turningpoint" tab and then choose "insert slide" to create an interactive slide.