***/// Creating this in CS...

Hi
I need some help. There is this photograph taken with a DSLR. After having adjusted, curves etc. I need to play with it a bit. The effect I want is like this. One half of the photograph must appear in monochrome(e.g. B&W). The other half would remain in color. But it should appear that there is a gradual transformation from monochrome to color. I know I have to use layers. Beyond that I don't know how to go about creating a gradual tansparent layer. Can anyone help me with this?
Thanks

I'll have this moved to Post Proccessing. For now, you need a Layer Mask which is built into the Layers> New Adjustment Layer (PS7) / Hue & Saturation. Reduce the Saturation to 0. Click OK.
Make sure that the mask (at the right) has a double line around it. If not, just click on it. Notice that it's white which means "Reveal All". Select Black & a brush at 100%, & just paint on the pic. See the result? That's all your looking for here, to see how it works. Undo the brush work in History.
To get an even gradation you should use a B&W gradient. Done that before? Make sure that the colors in the left are default B&W. Select the Gradient tool. Still got a double line around the layer mask?
Hold down Shift & drag the mouse across the pic. That should get you started. Good luck!

EDIT: I've done an example of this in this post where you can see the work done on the Adjustment Layer mask. I hope it helps.

Thanks a lot. That's really something new I learnt. Appreciate this.