Passing data between controllers in Angular JS?

I don’t know if it will help anyone, but based on Charx (thanks!) answer I have created simple cache service. Feel free to use, remix and share:

angular.service('cache', function() {
    var _cache, _store, _get, _set, _clear;
    _cache = {};

    _store = function(data) {
        angular.merge(_cache, data);
    };

    _set = function(data) {
        _cache = angular.extend({}, data);
    };

    _get = function(key) {
        if(key == null) {
            return _cache;
        } else {
            return _cache[key];
        }
    };

    _clear = function() {
        _cache = {};
    };

    return {
        get: _get,
        set: _set,
        store: _store,
        clear: _clear
    };
});