become a public speaker

I watched The Last Lecture on the internet for the first time. That was inspiring.

Today I visited a church and listened to the pastor who was such a good speaker. He was captivating and smart…people hung on his every word. I aspire to be able to captivate an audience in the same way.

I would like to become a speaker who can educate and motivate young people. I already work with children, but I would like to develop my skills. Any tips or references will be greatly appreciated!