Well, do you know what led to the discovery of Justin Beiber? (Sorry, I know, you may hate him) It was YouTube. A musician found out that Beiber had a lot of talent in him and called him up. He recorded his first song and that was a hit.
That is also what is transforming to reality nowadays. Talented young people are hooking up on Facebook, Vimeo, YouTube and other communities where their talent is noticed. I noticed a lot of Indian talent, too. I had taken a interview of a rising star via e-mail (whose name I can't disclose because the person requested me not to publish due to her privacy reasons), who had been selected for Indian Idol round 3. The person said that YouTube helped her to reach fame.
So the point is, video-sharing communities can earn you name and fame in a couple of days, or who knows, even minutes, maybe! If you are a professional in some area of work, share it in your channel. If, luckily, you get noticed, sponsors may even run after you!
But, as I said, that requires sincere dedication and hard work. If you sing, sing for fun, not thinking it will be considered while selections and trying to correct small mistakes here and there, for it can be recognized and it prints a bad impression on the judge/musician of the particular contest/show.
Got talent? Soar out to the sky! Reach new heights with YouTube, that's my guarantee, just remember- Original content!