We observe that existing methods for failure-tolerance are inefficient in their use of time, storage and computational resources. We aim to harness the power of idle desktop computers for data-parallel computations, which are particularly sensitive to failure, and propose spreadspectrum computation as a suite of techniques to mitigate failures in an internet-scale distributed system. Spread-spectrum computation will use computation dispersal algorithms to add redundancy to computations, in order that they may tolerate a particular failure distribution. In this position paper, we introduce computation dispersal algorithms, providing examples of their implementation and applications.