From what I remember you have the option to confirm the signup via email OR sms. So just use a fake USA number to sign up with and just confirm it via email.. see if that works.
Now that we've thrown 'em off the trail, use the form below to get in touch with the people at Engadget. Please fill in all of the required fields because they're required.
Maybe you should mention in your article that it's only for US users so far... :(
The forum mentioned this version is only for users "well, if your phone number starts with a 1," meaning US carriers only.
From what I remember you have the option to confirm the signup via email OR sms. So just use a fake USA number to sign up with and just confirm it via email.. see if that works.