Brandon and Sarah posted about their desire to have more space saver toys. Their comment thread brought up kitchens. This is the kitchen I'm going to make for Jackson someday. It's part of a showroom at the New Haven Ikea. It's built onto a simple shelf; black spongy coasters serve as "burners", there's a rubbermaid bin sunk in for the sink, and drawer pulls serve as knobs. Bonus--its not painted stereotypically girly pink. There's a little cupboard above it (optional).
I can imagine building this as a little piece of furniture on wheels so it can be pushed out of the way. For spacesaving, it could be built as a dropleaf kitchen shelf.