Skype launched a pay per minute WiFi access service in partnership with a number of
WiFi hotspot partners around the world. The list of hotspot providers does not appear to list any that operates in the U.S. However, if you are traveling outside of the U.S., it may provide a somewhat reasonably priced WiFi as needed service.
The name of the service is Skype Access. Payment is via Skype Credit at rates that start at 6 cents per minute according to Skype’s blog announcement. However, the Skype Access product page says the rate is a considerably higher 19 cents per minute.
At 6 cents per minute, an hour of use would cost $3.60. However, at 19 cents per minute, a hour of use would be $11.40. At that price, you might want to check WiFi rates in your hotel or some other local establishment.