Using ground flax, you simmer about one tablespoon milled flax seed with three to four tablespoons water on the stove top. The recipe says to simmer the mixture for five minutes but I've found that generally about two minutes results in a better product. This will replace one egg so adjust measurements keeping the one to three/four ratio for the number of eggs you need to replace. Also, remember to do this ahead of time so the "eggs" are cool when it's time to bake. The result is so amazingly egg-like that I could sit down with a bowl of cake batter and have dinner (without worrying about salmonella).
I've become so fond of flax in my baking that I rarely use eggs. I especially love the flax in my pancakes. So, a heads-up to anyone preparing food for someone with an egg allergy, people trying to cut cholesterol, or people looking to up their intake of MUFA's (mono unsaturated fatty acids), milled flax is a wonderful addition to your kitchen.