Examples of groups

Groups will have the role to bring more stability to the currency.

Some ways groups could work:
A group of a small city: a number of business owners could come together to start such a group. They could have a centralized process where you would register by appearing physically in one of the businesses.

Centralized groups with a n out of m voters rule.

Decentralized groups where the majority/x% + quorum can add new member.

Web of trust rules.

What is the implementation state of Circles Groups?