A simple RUT(chile) mask for Angular.

directive.js

angular.module('olaferlandsen', [])
.directive('ngRut', function() {
    return function (scope, element, attrs) {
        element.bind('keypress', function (event) {
            var value = element.val().replace(/[^0-9k]/ig, '');
            if (value.length == 9) event.preventDefault()
            if ( (event.which >= 48 && event.which <= 57) || event.which == 75) {
                // reemplazamos todo lo que no sea parte del rut
                // establecemos el guion medio(-)
                if (value.length == 7 || value.length == 8) element.val(value + '-')
            }
            else {
                event.preventDefault()
            }
        });
    };
})