If you've got the opportunity to take the photos you've described in your OP, it'll end up looking far better, and be far less work than the methods they described (they're talking about copying/pasting a single image of the person multiple times in the photo.
If you can, use a tripod, shoot the images with the person in the places you want, then bring them all into photoshop. Pick one of the images to be your "base", then:
"Layer->Duplicate Layer..." to stack each image with the person in a new position in your "base" document then:
Change "Layer Opacity" to 50% to tweak image alignment if necessary (or try "Edit->Auto-Align Layers"
For each 'new position' layer, follow the tutorial here to remove the background:
http://photoshoptips.net/2006/07/25/layer-masks/