Stongly recommend
I have been involved with TI (Toastmaster International) for several years. I still constantly fight with my own inertia to get my speeches (speak in front of a live audience) done. However, it is a very rewarding experience. Now, I feel very comfortable speaking in public and I can come up with topics very quickly as the result of the "table topics" training in TI. I found a teaching position in a US university because of my training in Toastmasters.
You can go to TI's home page to find a local chapter to try it out for free. You need to pay a membership fee to join the club, but it is well worth it.