1. Folding Crates from the Container Store collapse and come with optional casters.
2. The Umbra Crunch Can is easily scrunched down to a few inches but when it's open it can store a ton of toys, laundry, or stuffed animals. Handles make it portable.
3. We've mentioned the Reisenthel Market Basket before. The kids version has a drawstring to keep things contained and the basket collapses to save space when not in use.
4. The Komplement basket from IKEA can adapt to many different areas of the home and folds flat.
5. Target's itso Large fabric bins will fit your IKEA Expedit; plus, they're sturdy and fold flat.