The new guy on the block in vacuum cleaners loses the vacuum bag in favor of a whirlwind that deposits dirt directly into a holding tray. It's called cyclonic action, and Dyson claims to have invented this revolutionary approach to floor cleaning 30 years ago. There are a number of models using this technology, some better than others. If you're in the market for one, Consumer Reports has reviewed a number of them, giving each one a rating out of 100. All have pros and cons, so do your research before you buy one.