I find it interesting when learning about someone if they can share something personal/special to them with me. A photo, a drawing, something they've made, a souvenir from a special trip etc.. It really personalizes the speech and gives your audience a glimpse into who you are. It adds that special touch to make your speech memorable and unique from everyone else's.
Bear in mind though that the item would need to be a good size for the back row to see it, yet small enough to lug around and not be too distracting. Avoid passing it around while you speak, but perhaps make it available for them to take a closer look at afterward.
I wish you the best of luck with it, I know it can be nerve wracking.
