What program are you using? I use Photoshop CS. In there you could use the marquee tool. In the options bar for the marquee tool (along the top of the window), you can tell it to do a Fixed Size, 2 in X 2 in. When you click on your layout, a 2X2 square of marching ants will appear. Then you just have to select the layer that you want to crop, move the marching ants to the area that you want to crop. Then, go to the Select menu and choose Inverse. This will select everything BUT that 2X2 square that you want to keep. Hit delete. If you already have all the photos that you want to use on your layout, just select the next layer that you want to crop, move the marching ants again, select the inverse again, and delete again.

Hope that made sense!

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