Thanks for your comments guys,
I did some research on this, and looks like for some models you can program it yourself, especially the Keyless remote as seen in this video:
But unfortunately this doesn't work on my 2008 Tiida.
As 'toyota sucks' said I also don't like giving my keys to a third-party locksmith. But it is far too better than wasting 28K to the company. If I had known the thing is worth that much, I would have stored the damn key in a locker and kept it under the pillow when I'm sleeping.
So I'm thinking of getting a blank key straight from Japan/China and let the company do the programing work. I hope A*W folks woudn't mind that.
Cheers,
SunLikeStar