Re: Adobe Photoshop Elements 6 on a MacBook: how can I reduce a document's image size and then fill the original document size with many of the down-sized images?

With Photoshop you would simply create a new page that is 12×12 at whatever dpi your original docs were and then copy the reduced images or drag the reduced images onto the blank page. This creates 4 layers plus the original background and you can flatten the image or create a psd file which remains editable easily. I would assume you can do the same with elements, I think that is a reasonably sophisticated app.