Thanks, I'm going to give these a try. Adding one behind the seat to allow me to clip stuff in would also be pretty handy.

Make lots - once you start using them you will realize how useful they are, and start adding more. It's a good way to use up scraps.
Locations:
Behind the seat
On the sole in front of the seat (between your legs)
Inside compartments to keep water bags in place
Under the deck forward of the cockpit
etc.....
And your friends will want some also.....
:-)