The ripple version of trust you mention is one way to go but i think it's no surprise that it's being adopted by banks. It's basically the same idea of how they operate today just with a few more bells and whistles.

Steem on the other hand has created a value token that has trust linked in a different way. It has digitised the concept of trust and reputation and built a system of decentralised governance around it. This in one of the reasons why steem sands out among the cryptocurrencies for me.