What are applications of error-correcting codes in theory besides error correction itself? I am aware of three applications: Goldreich-Levin theorem about hard core bit, Trevisan's construction of extractor and amplification of hardness of boolean function (by Sudan-Trevisan-Vadhan).What are other 'serious' or 'recreational' applications of error-correcting codes?UPD: one amusing application of list decoding of Reed-Solomon codes is a solution to particular variation of 20 questions game (and another, more straightforward, variation).
Using error-correcting codes in theory
co.combinatorics;big list;coding theory