One of the items we bought for the homefront was Magic Baking Powder (From Kraft). It’s basically soda and it is used for leavening batters. Perfect for example to get your white cake going: in those cases you definitely don’t want to use other agents like yeast. Note, baking powder does perfectly well in scrambled eggs too: a half a teaspoon makes more out of the eggs. Trust me.
Before I came over here, I had never heard of baking powder before: generally, I was taught to make cake using plain sugar, eggs and flour and milk. In those kind of recipes, it’s the beating of the eggs that makes the cake rise: imagine my surprise when I saw the effects of soda. No more 20 minutes of beating eggs!
For the chemistry gifted (and the ones that are familiar with this stuff): baking soda is plain NaHCO3 (sodium bicarbonate). You may remember mixing up soda with vinegar when you were younger and looked up amazed about the bubbles. Well, magic baking powder is the same, except for it has (extra) dry acid, which gives notably better leavening results than plain baking soda while using less of it (soda is generally saltier too).