Arts supplies (your kids or yours) won't take over your whole house if you provide a compact vessel for them. This three-tiered kitchen cart (from IKEA) stops your collection from growing exponentially, and looks surprisingly cute even when stuffed with paints and papers. See more at I Just Might Explode » - WomansDay.com
Storage made from cardboard. Could be an idea on how to either store a greater amount of work, or showcase an entire collection perhaps, in a space-saving way. Would have to be a great deal smaller, possibly just one of the columns (1/3 of the piece).