The idea of municipal Wi-Fi service in the United States has been always been a hype magnet as local politicians could claim altruism while tapping a new revenue source and the technical crowd could follow a vision of ubiquitous Wi-Fi, while making money on the deal. The jury is still out on whether municipal Wi-Fi will ever amount to more than a passing fad, but Microsoft got involved yesterday when they revealed an alliance with mobile advertising provider JiWire to offer ads on municipal Wi-Fi networks: