I happened upon this tip at the library yesterday. It is from Cooking with Herbs: 100 Seasonal Recipes and Seasonal Mixtures to Spice Up Any Meal by Tina James. It is for herbs that have a high water content, like basil or parsley. Wash the herbs and allow to thoroughly dry. Place several stems in a single layer in an unopened paper bag and tape this to the side of a frost-free freezer. In a week, the herbs are dried because the defrosting function removes the moisture from the herbs as well as from the fridge. The cold temperature also is said to preserve more flavor.