Homemade, washable baby wipes
This may be the only reason to buy a wipe warmer. Here's how Meghan uses one to keep her homemade baby wipes bum-ready:
We make our own baby wipes using cheap baby washcloths (e.g. Gerber) and a wipe warmer. We put some water in a wipe warmer and it keeps the wipes moist and warm. We have a pile of washcloths and wash them along with the cloth diapers (usually every other day). For now, since our daughter is a newborn, we use plain water. As she gets older, we'll add a dash of baby cleanser to the water. Works like a charm! Be sure to use the cheap-o washcloths -- they're thin and flimsy and perfect for butt-wipin'!