I use Northern Essence Natural Diaper rash salve. I received this stuff as a baby shower gift and I swear by it. When my son was a newborn, he got bad diaper rash from all those runny diapers, and this stuff really cleared him up quickly. It has a really pleasant smell and the best part is that it came in a tube so you just put it on like deodorant. We use it every day for prevention.

My friend cloth diapers and she uses it because it doesn't affect the absorption on the diapers.

http://www.northernessence.com/catalog.php?category=24