Low Carb Resources
USDA nutrition database -- can give you a full nutrition breakdown on any food item.
Atkins Diet & Low Carb Weight Loss Support -- lots of information, news, carb counter
LowCarbFriends -- support, information, news
Cooking TLC -- information, recipes, a few unique products
Low Carbohydrate recipes, a nice selection
Low Carb Cafe -- recipes, chatroom,support
3 Fat Chicks -- although this site isn't strictly low carb, it is divided into sections by diet and has lots of useful news and information.
Low Carbohydrate Recipes from the alt.support.diet.low-carb group. Good-sized recipe collection.