We've just launched or Charlton Park iPhone application - it's free and it will be one of the services that can take advantage of the site-wide Wi-Fi.
If you would rather not be without the internet for a whole weekend then fear not as WOMAD Charlton Park has it's own WiFi network. Access to some pages, such as pages this website and the iPhone application will be free. Charges apply for wider access. Lets get Twittering.
1 day: £5.00
All weekend 23rd - 26th July: £10.00