(Simple) shadow of 2D Textures (Tiles), behind the textures

Question

I'm developing an app for the XBOX 360 using XNA. I'm trying to keep it very simple and metro-style.

My tiles are arranged like this: http://gameplay-video.com/wp-content/uploads/2011/img_2462_xbox-360-dashboard-update-sceens-5th-dec-2011.jpg

And what I want to achieve, is using a grey/black background like the one in the picture, but with the same shadow.

I believe the lighting point is behind the tiles, the tiles themself should not have an inner shadow. However, they should have a shadow at the bottom, as seen in the picture (the small darker line at the bottom)

I'm no expert in XNA, this is my first application (which is going pretty good atm), but I'm willing to learn.

Answer 1

I think the simplest way would be to draw the tiles twice, the second time they would be black and scaled (and offset) down on the y axis, using a blur shader of some sort.