You may shiver just from observing, but is there a more traditional way to kick off the New Year than watching a bunch of people dive into frigid waters on Jan. 1? That's when the annual L Street Brownies' polar plunge takes place. Last January, about 500 people dived into 39-degree waters of Boston Harbor, with about 1,000 others satisfied enough to enjoy the view with most of their clothes on. Free. Your eyes may have to pay though in witnessing some midwinter potbellies.