Got asked by Mel how to use this wonderful tool I've just discovered, so thought to help everyone out by publishing this mini tut.
HOW TO USE THE PERSPECTIVE TOOL
1. Ensure you have the element and dropshadow in seperate layers and select the dropshadow layer.
2. Select Perspective Tool (Shift+P)
3. Click and drag the corner handles to your liking.
4. When you are happy, select Transform from window.
And how do you find the result???