Ashley, which version does it work on for you?
I pulled out my network cable, switched off wireless (have HW switch), and tried to hit a page (e.g. google) to check it failed. For the phones and ipads, I simply siwtched off my ADSL wireless router, then checked i could not access any web pages (there are no other access points near me). I tried on iphone4, iphone 3, ipad2, PC with chrome and FF.
I would be very excited to get this working, as it would really help the app.