Don't forget to think outside the box - "worn out" cutting mats might be refreshed with a long soak in warm water (good maintenance technique - they wear out because they dry out and cuts don't "heal"), bleeding fabrics might be just what an art quilter wants so she/he can play with the bleeds in a quilt, etc. Quilt guilds usually have a "free table" where one can put out items for others to take - just be sure to add a note of any unique feature (bleeds, nick in blade, etc.)