I ride in a wool sweater or my Ibex Switchback full-zip if it's cold. I yearn for an Ibex Breakaway. (apropos name for a cycling jacket, eh?)

Edit: my boo-boo, they changed the name this year to "Dash." Here it is, http://www.ibexwear.com/shop/Product...-Hybrid-Jacket You can still find Breakaways at some of the outlet type online stores (Sierra Trading Post, Backcountry, Camp-Mor, and the like) for about half price of the Dash.