<shameless plug><p>I've been working on an idea similar to this for a few months. Instead of limiting this to crypto currency mining (a fair application, FWIW), why not approach this with the idea that people plugging in their phones every night could easily constitute the <i>largest</i> distributed supercomputer ever built? Everyone has the same nightly ritual: Wake up, use phone/tablet/device, plug in at night. Once it's plugged in, your phone charges to 100% after a few hours, and then essentially sits there for x hours effectively doing nothing (that's a little sensationalist, but it highlights my point). Folding@Home, et al have done this before, but the silver bullet here is that no one turns off their phone when it charges at night - perhaps to maintain the off chance they receive a random 4 AM phone call.<p>Now if you can combine this with an SDK (say... something Javascript based) that makes it easy to write/deploy compute jobs/"apps", you have a real distributed computing platform. You can also maintain security by using a similar proof-of-work scheme that bitcoin uses to prevent fraudulent mining.<p>The real challenge here is incentivizing people to run your app. Here's my sign up form for an early private beta for anyone who is interested.<p><a href="http://stynt.co" rel="nofollow">http://stynt.co</a>