underscore-once.js

var db = {

  // will be called only once
  connect: _.once(function() {
    /* .. do something .. */
  }),

  find: function(id) {
    // lazy connection
    this.connect();

    return /* .. something .. */;
  },

  findall: function() {
    // lazy connection
    this.connect();

    return /* .. something.. */;
  }
};