Result:
Click here to view!

Alright, i have been asked this question many times nowadays, 'How do you get that glassy effect on your work?' And my answer to that question is this tutorial :P. I hope it teaches you guys a lot and help you guys get creative with your work.

1. First you need something to have a glossy effect on, i'm going to use this:
Image

2. Now that you have your render/picture or whatever, lets add in that glassy effect. First create a new layer:
Image

3. Now get the Elliptical Marquee Tool (M) and select a large oval shaped selection, it should take up about 3/4 of your page.
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4. Next, keep the selection there and get the Gradient Tool (G), and make sure your foreground color is white and have the top settings as what follows in the screen shot below:
Image

5. Now using the Gradient Tool, make a straight line from the top middle of your image to the end of your selection that you made. And you should have something like this:
Image

6. Now Deselect
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This concludes our tutorial, you should have something similar to this:
Click here to view!

Here are some other examples of what you can do using this tutorial:
Example 1
Example 2

Download this tutorials .PSD file here.