In Washington and British Columbia most marina''s and resorts are set up with Broadband Express (www.bbxpress.net). I have been anchored out a half mile from the transmitter in Ganges Harbor and still been able to get online. They are adding sites each year and there are other Wi-Fi providers in the area. With the 200mW cards you can connect at a far greater range than I can with my standard 30mW card. BBX has account plans for the day, month, and annual. Since the same service is available in many marinas and some harbors, I am on the annual and am pretty happy since my previous DSL and Cable were not so consistantly fast.
The FCC just made some new bandwidths available that can create networks up to 5 miles across in order to stimulate broadband access for people in rural areas where no cable or DSL is available. I bet in a few years some of these wi-fi companies will adapt this to make it easy to connect in more places.