When it's hot like today, a fan is kinda cool, but a USB fan is so much cooler. So to build a USB fan we need: a basic fan bought from the nearest appliance store, a Yocto-PowerRelay, 15 minutes to properly install the device in the fan, some more time to code a nice web page to control it, et voila! a nice USB fan remotely controlled from your desk. Have a peek below...