As it turns out, I've decided to write tutorials again. Here goes.
This one will help you create reflections for pictures, useful for web page headers and such.
Step 1: Create a new document. Make it nice and big to work with (at least 1024*768). You can always resize later.
Step 2: Open your working image. Ctrl+A and then Ctrl+C.
Step 3: Select the New Document, and paste it there. Ctrl+T to resize to a workable size. Rename this layer to alpha.
Step 4: Ctrl+J to duplicate alpha. Then with alpha duplicate selected, hit Ctrl+T and then Right-Click in the middle of the image. Select Flip Vertical.
Step 5: Drag the image down till there is a small gap between the two.
Step 6: Select both Alpha copy and alpha in the layers palette. Press Ctrl+T.
Step 7: Right-click in the middle and select 'Perspective'. Now drag either of the four corners up OR down depending on which side you want the angle to be.
Step 10: With 'alpha copy' selected, go to Layer > Layer Mask > Reveal all. A white box will appear next to the 'alpha copy' layer.
Step 11: Make sure that you colors are default (press D), select the 'Gradient Tool' and select Foreground to Background from the gradient type menu.
Step 12: Make sure that the Layer Mask is selected in the layers palette, and drag from somewhere in the middle of the top image to the middle of the inverted image. Keep experimenting till you get a good result.