We have an Oreck at home. http://www.oreck.com/air-purifiers/xl_air_purifier_tabletop.cfm. Kind of pricy, but I did notice a big difference when we started using it. One thing though, it has a deionizing setting (blows negative ions into the air, causing particles to lose their positive charge and fall out of the air-or maybe that's the other way around). Seems I see more dust when that is turned on. I guess the theory is that it is better that it fall to the ground than stay in the air.