Do you have a high-efficiency front-loading washing machine? If so, be on the lookout for mold. This recently-published MSNBC.com piece investigates the increased likelihood of mold growth in front-loaders. Unlike top loaders, which see most water evaporate after a cycle, front loaders experience water collection, particularly on the rubber gasket around the glass window. And all those advanced physics students will recall Einstein's lesser known theory of mold-time continuum: H₂O + Rubber = Mold˛.
Certain washing habits don't help the problem, either. The use of less bleach and cold water cycles can contribute to mold growth, which leads to stinky washing machines, stinky laundry rooms and stinky homes.