If you're a computational engineer, there's no question about what you do with the Raspberry Pi: you make a supercomputer cluster. Researchers at the University of Southampton have followed their instincts and built Iridis-Pi, a tiny 64-node cluster based on the Raspberry Pi's usual Debian Wheezy distribution and linked through Ethernet. While no one would mistake any one Raspberry Pi for a powerhouse, the sheer number of networked devices gives the design both some computing grunt and 1TB worth of storage in SD cards. Going so small also leads to some truly uncommon rackmounting -- team lead Simon Cox and his son James grouped the entire array in two towers of Lego, which likely makes it the most adorable compute cluster you'll ever see. There's instructions to help build your own Iridis-Pi at the source link, and the best part is that it won't require a university-level budget to run. Crafting the exact system you see here costs under £2,500 ($4,026), or less than a grown-up supercomputer's energy bill.