I am an avid user of fon and if fon is not available use Skype out to get connected, with my Wifi-only iPad.
The only problem is to locate the closest Wifi point. It is a chicken-egg problem. You need Internet access to find Internet access.
Is there an app, or downloadable file, with all Wifi locations, to be browsed offline?
I would also settle for a social-media solution where the users share their wifi connectivity while traveling. As long as it allows caching for any given location.