Long before WiFi was part of our vernacular, most houses had their share of hot spots -- and cold ones too. For less than $40, you can boost the air flow in that back bedroom that's always been too cold (or too hot).
Installation is pretty straightforward. Remove the existing vent, drop the booster fan into place and plug it into a nearby electrical outlet. It turns itself on and off automatically by sensing air flow at the register.
Air flow can be boosted by up to 85 percent, according to the manufacturer.