Sorry for the quality of the images, I have no idea why I used my cell phone instead of my DSLR that I had laying right in front of me (DOH!)
Step 1: What you will need...
A Backpack. I wanted one to carry my laptop as well as my camera so I searched for one that specifically was made for laptops. I discovered that the ones made for laptops seemed to have more padding already built in.
A nice pair of sewing scissors (you know, the ones your mom/wife/girlfriend has hidden away from you!)
1-2 yards of soft material to cover the dividers.
A glue gun or sewing machine. I used a glue gun to bind everything together, a sewing machine produce something neater but I didnt want to take the time to bother the wife with sewing up a bunch of unknown and possibly changing ideas off the top of my head.
A large roll of 3/4 or 1 inch wide Velcro, I ended up using about 5 feet total. Get the type that has the sticky back.
Stiffening material, I used some 1/8th inch thick coroplast board (corrugated plastic board) , its sort of a plastic cardboard. You could use some thick cardboard or maybe even some poster board material.
For the foam I was able to score some 2 foot by 2 foot by 1 1/2 inch thick and some 1 inch thick stuff from work for free
For the soft material, I used a body pillow case, I caught it on sale at the store and they came 2 in a pack. I figured it was about 2 yards of material but I only used about 1 yard worth. You may use more or maybe less depending on how many dividers you build.