> Even Bitcoin has provided useful work for a very weak definition: it has created incentives for MASSIVE research and development in cracking or otherwise brea

> Even Bitcoin has provided useful work for a very weak definition: it has created incentives for MASSIVE research and development in cracking or otherwise breaking SHA-256 And chip performance in general. It wouldn't surprise me if Bitcoin ASICs nudge the state of the art in chip design and fabrication forward. Another (very marginally) useful bit of work mining does: converting electricity to heat. I doubt many miners are currently using the heat, but it seems inevitable that eventually most miners would be located in areas where 1) electricity is very cheap, and 2) the heat produced by mining can be used productively