Since I love the idea of standardized ERC20 tokens but I hate the ICO distribution model, I developed a reference implementation for a standard Ethereum token that can be mined using Proof of Work via a smart contract.  This way, we can return to the days when a new blockchain asset is simply mined.  I also see this as more important as Ethereum moves away from Proof of Work and leaves a void for GPUs and mining rigs everywhere.  Instead of PoW mining ether itself, the tokens can be mined. 

https://medium.com/@admazzola/the-case-for-the-mineable-erc20-token-78cbb4c34331