I often use yogurt instead of buttermilk or milk in muffins and quick breads (such as the better banana bread posted here) and have always been pleased with the results.

using yogurt will help relax the dough much more because of its acidic content but you may need to add a little bit of a sweetener to compensate for taste

I had a recipe for a lime pound cake that I wanted to adapt since the first go round was dry. I added 2/3 cup of plain yogurt and was very pleased with the result. I overbeat the batter a bit, but the cake was still very moist. I'll do that again when I make it next, but I'll use a wooden spoon to mix the batter rather than an electric mixer.

You should be able to easily replace whatever milk or sour cream is asked for in a quick bread or muffin recipe with yogurt. Your results should be moister.

MadP

Check out my favorite baking site http://www.fortheloveofbaking.com

I use Kefir milk, a product which has many similarities to yogurt but is healthier, in any  breads (quick, sourdough, yeasted) that ask for milk and it is incredible. Also makes a great poolish for Ciabatta too.

Incidentally, the most moistness I have ever achieved was by using sauerkraut in the recipe, it works well in cakes but have not tried it in quick breads. 

I have gone to the Kefir Grains website several times requesting a starter from people that have offered it.  In all the times I have tried (at least 9 times) no one has ever contacted me back about getting some culture.  I am interested as I have heard it is great with sourdoughs due to its acidity.  Can you direct me where to get some kefir grains to get started?  Any help appreciated.  Thanks 

Rena in Delaware

I use yogurt almost exclusively in quick breads instead of milk. It's moister and more flavorful to my palate.