With the release of the first beta for iOS 7, many are flocking to third-party UDID activation websites, but for no real reason. Avoid that altogether by following this guide.
It turns out that a simple update will allow iOS to skip the UDID check. There’s no telling if this will work on future versions of the iOS 7 beta, so only time will tell.
I’ve confirmed three times that this method works, whereas the normal restore to iOS 7 brings up a message saying how my device was not a part of the iOS developer program.