I would suggest just doing something in front of people at every oppotunity! Go to karaoke bars and sing in front of people. Take a couple of speech seminars that target stage fright. Join a drama club or class. Anything that gets you in front of people.
Also, try not to think about what others will think of you. Think about how much you love this and you want to share it someone. It might help. Breathing exercises help too.
Hmm, I guess this could be really helpfull...I will try to look for something like this ( although in our small town, it will be problem ). Actually I´m shy person, I was never kind of person who would want to perform in public and I guess I wouldn´t start to dance in public if I wouldn´t have to start to perform with fencer´s group...I walked through the worst with them, and realized that I want to perform with dancing. But still I have something from this "rather die than get in front of people and speak" also in mind