According to Washington Business Journal, fourth-generation wireless internet provider ClearWire has turned on their WiMAX service in D.C., ahead of other East Coast cities such as New York and Boston. Under the “Clear” brand, Clearwire is offering an “On the Go” deal for $40 a month, which you could theoretically hook up to your laptop and be set anywhere in the city that has coverage. For $59.99, you could get a free 3G/4G dongle from…