mtnlvr68,

(I hope none of you take this the wrong way!)

I am not encouraging anyone to carry more stuff. However, some of my kit is in compartamentalized bags inside the main pack. While I do leave a little room, depending on ammount of clothing for expected weather, the organizer bags my types of gear are in can easily be emptied into my pack and/or pockets, thus giving me more space to pack once I attach the organizaer bag to the exterior of my pack. Once I have setup an exterior atachment system for one of the bags, the 550 cord used is put into the organizer pouch for storage.

One example of needing more space.
So, If I am Hiking and suddenly become disgusted with all the trash others have neglected to packout, I have the needed space to clean up a little. (the trash bags I carry for emergency ponchos can still be used as trash bags too!)