There may already be a thread on this somewhere (but I haven't found it), so I apologize if I'm being redundant. For a cheap CCF pad, instead of using a full, sewn fabric pad extender, what about simply making wings with ribbon cable? Same idea as an SPE, different method of doing it. You could cut a small slit on the pad and the wings, loop the ribbon through the pad and the wing, making a hinge to hold the wings in place. It would probably be more durable than tape, and lighter/easier (I don't have a sewing machine) than a SPE. For two wings (one on either side), you would only need 4 pieces of ribbon maybe 3" or 4" long. For packing up, you could easily take the ribbon loop out to roll up the pad, and stash the wings. Easy. Thin rope would work as well, but ribbon cable could be more comfortable.
Sorry I don't have any pictures or diagrams, I hope the idea came across. I also would try this myself immediately, but I'm studying for a semester in Singapore, sadly away from all my gear. I'm planning an AT thru hike after graduation (2011) and want an inexpensive insulation option that can also translate to shelters.
What do you think? Any shortcomings in this idea? Would the ccf rip? Thanks!