How about using domain names as proof of stake? I think it is perfectly possible.
maybe not as decentralized as proof of work but certainly more decentralized than proof of stake because the coins are not created all at once.
we use an internet asset to create an internet coin.
IMO it's also prone to centralized, especially if all top level domain is treated equally. Government (such as ".uk" and ".sydney") and rich individual/company (such as ".aaa" and ".sucks") who have their own TLD could create bunch of new domain solely for controlling network or earn bunch of coins.