Flaxseed - substitution

According to the Mayo Clinic you can substitute ground flax seed for one large egg in a recipe, use 1 tablespoon ground flax seed plus 3 tablespoons water. It will somewhat alter the texture of the finished product, making it slightly “gummy.” Apparently it works well in breads, cookies, casseroles, etc. If the recipe calls for all purpose flour, it will probably work. Golden flax has the same nutrients as brown flax but blends in better with some recipes. The nutritional value is greatly decreased the longer they are ground and just sitting. Source

Since finding this information out, I've substituted flax seed for eggs in cake, brownies, cookies, bread and they've been wonderful every time.