find a 3 ring zippered binder (back-to-school sales)
fill it with regular heavy duty sheet protectors for your circulars.
you can label each pocket easily with a magic marker with needle
size (US AND mm's). this binder contains only 24" lengths from
US 2 to 17 and is a perfect travelling companion.
I have been told that there are zippered 3-hole punched pockets
available at fishing tackle stores.
rolled up double point case, closed with a broccoli
rubber band makes for secure (though not elegant) travelling.
if you can sew
or know someone who can, needle cases are easy to make. though they
are a little time
consuming, all the stitching is straight and you can customize the case for
your own tools.make room in your design for crochet hooks, cable needles, folding scissors, writing devices, whatever you like to have on hand.
make a taller case for straight needles.