Sorry to hear that Keith, I was rooting for you.

I too think you shouldn't give up. Just because there may be other competitors doing something similar -- even giants you feel you could never tackle -- doesn't mean you don't have something unique to offer that the competition doesn't.

Also, even if you don't topple the competition, who cares? If you have a product that others are interested in, your product has the ability to be much less successful and still yield you more of an income, just because you have much less overhead than the giants.

Worst case, you'll come out of it having gained a lot of experience -- you'll know the technology better, and will have learned some good life lessons. Then you'll be better prepared for the next YC app!