Not all farmers' markets go into hibernation when temperatures drop. Log on to localharvest.org to find one near you that operates year-round. Stock up on fresh winter veggies (beets, kale, winter squash, leeks, and parsnips, for example) as well as greenhouse-grown produce. While you're there, look for frozen goods; many vendors freeze their spring and summer produce at the peak of its ripeness. No farmers' market close by? Head to the frozen-foods section of your grocery store. The produce there often has more nutrients than a "fresh" vegetable that has traveled across the country to get to your supermarket.