Here is another cool case for your DIY Raspberry Pi projects. The C4Labs Cloudlet Case has 8 bays to hold single board computers or 2.5″ hard drives. You can bolt multiple units vertically or horizontally for modular clusters. The case has 4 50x50m fans for active airflow.
This Raspberry Pi case is made of double thick acrylic. It costs under $50 at this time.