This is a design for a notepad made out of diamond plate and rubber bands. When I have ideas I am usually scrambling around to find a scrap of paper to write them on. I started carrying around index cards, but they would get mangled in my pocket and they were hard to hold while writing. This solves the problem by sandwiching index cards between two pieces of diamond plate.
Step 1: Materials
Obtain the following
-A piece of 1/16 inch aluminum diamond plate at least 11" x 8", you can find this at your local home improvement store or online. It is fairly expensive so shop around.
Step 2: Cut and Sand
Cut two pieces from the diamond plate that are 3 1/4" x 5 1/4". I suggest using a skip tooth blade on a band saw. You will end up with rough edges all around. File and sand them down using progressively finer sand paper. Make sure to make a radius on each corner as to not rip your pocket.
Step 3: Attatch Index Cards
Take one of the plates and attach index cards by using two rubber bands over the sides.
Step 4: Finish
Now take the other plate, place it over the index cards and place another rubber band around the whole thing.
Step 5: Conclusion
You are now done. To use, grab the notebook horizontally with your non writing hand, slip the rubber band off and over your fingers and take the top plate and place it below the bottom plate. When done, put the plate back and slip the rubber band back on from your fingers.
This setup fits quite nicely in my back pocket and the aluminum is virtually unbendable. I imagine you could also use it as a wallet by attaching your cards and money to the top plate with a few more rubber bands.