can cryptocoins be put to good use? now or in the future?
Primecoin is an example of a well-known cryptocurrency that is doing something useful. As its name implies, its utility relates to prime number discovery:


  The innovative prime proof-of-work in Primecoin not only provides security and minting to the network, but also generates a special form of prime number chains of interest to mathematical research. Thus primecoin network is energy-multiuse, compared to bitcoin network.