There was a recent article on HN about Self and its prototype patterns. Looked far superior to Javascript's. But even still, prototypes only seem primarily useful if you want member-access as dot-notation or polymorphism by type. When preferring composition over inheritance, most polymorphic-by-type situations either go away or can be trivially replaced with maps.

That said, CoffeeScript provides another interesting use for them: Simulating dynamic binding. Basically, the trick is that `this` becomes the dynamic binding context and `@` represents a dynamically bound variable. You use `fn.call @, x, y, etc...` if you want to pass the dynamic binding to callees. Nested bindings can be established with `Object.create`