Re-usable Blade Snap Case
The OLFA® DC-4 is a great tool for snapping off blades when they blunt. Squeeze the top to open a slot at the top, insert your snap-off cutter into the slot (with the blunt segment extended) and pull towards you to snap it off and let it fall inside. Once you let go the gap seals so the blades can't fall out again.
Once you eventually fill the case up with blades, you can unscrew from the centre, empty the case and screw back again for re-use.