adobe photoshop - Perspective manipulation

I'm trying to achieve the effect shown below, but with a photograph and I'm having some trouble maintaining the height width ratio so the photograph doesn't look too distorted - can anyone offer any tips or tutorials?

Thanks in advance for your help.

Answer

To make that perspective effect look natural you would first have to stretch the right part of the image and compress the left part of the image:

+---------------+    +-------------+
|   |   |   |   |    | |  |   |    |
|   |   |   |   | -> | |  |   |    |
|   |   |   |   |    | |  |   |    |
+---------------+    +-------------+

Then you can just deform the image by moving the left corners togehter.

If you look at the example image that you posted, you can see that this hasn't been done there, so the left half of the image looks stretched. It's not as obvious on that image, as the left half only contains text, but on a photo the effect gets more visible.