Toastmasters International is a non-profit organization focused towards developing and enhancing public speaking skills. I had come across some of their videos of accomplished speakers a few years ago and was blown by their delivery, diction & style. Every city around the world will have a Toastmasters club that meets weekly and where public speaking is practiced, honed and critiqued. With 12500 clubs in 113 countries over 260,000 members, it is the best forum out there to develop public speaking.
One of the first things I noticed upon joining Infosys a few months ago was that they had a Toastmasters club. Sufficiently piqued, I started attending the Infosys Toastmasters Club (ITMC) meetings as a guest and then transitioned to a full-time member recently. I would strongly advocate becoming a member. What you learn in these meetings is the structured approach towards being a better speaker. Every new member is given a starter kit that outlines the specifics. And the best part? Every time you walk up on stage and speak, someone in the audience observes you & provides feedback. Together, we all grow into better public speakers.
You can learn about Toastmasters here.