Instructables.com has an extensive collection of do it yourself projects. Some are pretty far out, some would fit in better a dorm room than in a mansion. But they all provide ideas to build on.
Here are links to some compost bin ideas that may be just what you are looking for:
First there's an Overview of Compost Bins on Instructibles.com. followed by a Compost tumbler on a stand, a compost tumbler that is not on a stand, a different version of a compost tumbler on a stand that uses a standard garbage can , a double deck tumbling compost bin and finally a classic compost bin made from pallets.