Since I didn't see a reply I thought I'd tell you just google how to use
layers in photoshop.. should be really easy to learn and you could get exactly what you want by doing it yourself. Google some examples and photoshop walkthroughs that use layers.
I have absolutely 0 creativity being 100 percent left brained computer science major or I would do it for you. Hopefully someone else will chime in. Anyways just wanted to get you a reply and good luck!
You can get photoshop trial version for 30 days free or just torrent it.
bump
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edit:
reading my post i was a little vague in pointing you in the right direction..
In that picture you showed all they did was have a background image ..layer1
Then it looks like they just used the lasso tool or quick select tool to cut out the gsd from other pictures and then added them as new layers on top of the background image.
You can order the layers to have "on top" priority.
Hope this helped more and once again good luck!