Most Methodologies were designed to support the needs of very large teams. Although some of them are scalable, few can scale down to small team sizes. Minimal Methodologies on the other hand are designed to support the needs of very small teams (typically 10 people or less). They are designed to be human scale, providing just enough rigour to support teamwork.
A example of a Minimal Methodology is Extreme Programming, and this talk includes an experience report from a high profile project where Extreme Programming was used effectively.