It will create an effect that will make it look like something is walking right out of a picture, like this:
First, find a picture where it will look natural for somethign to be coming out of the picture - in this case I am using this picture of an iguana:
Duplicate the layer so you have two layers that are the picture
Next create a new layer and create a shape similar to what I have here. This is going to be the frame of the picture, so the parts you want to be coming out of the picture should be out of this box. The shape gives the picture a somewhat 3d appearance.
Select the black box and then select the second picture layer. Invert the selection and hit delete so all that remains is the picture that is in the shape of the box.
Move this layer above the black box layer. Then select the black box layer and use the magic wand to select the box. You can then use the "move selection" tool to elongate the box so that it creates a white frame around the picture.
Once this is done you can then merge these two layers together so you should now have a layer that has the whole picture on it and one that has a framed out chunk of the picture.
Move the whole picture layer on top of the framed picture layer and then hit F4 and change the opacity to 150. This will allow you to see the framed picture underneath the whole picture to use as a guide.
Then use the lasso tool to select the parts that are out of the picture, making sure that you are going all the way to the picture so that none of the white line shows. You can hold down CTRL and select more than one area - on this I selected the head and the foot.
Once you have the sections selected, invert the selection and delete everything else in teh top layer. Then go in and change the opacity of the layer back to 255.
On mine I then flattened out the image and changed the background to black so you could see the white border of the picture better.
And again, here is the finished product.
Best of luck
