If you're not a registered Apple developer and are considering installing iPhone OS 3.1 beta 2 acquired from a (ahem!) third-party source you may want to re-consider. A source tells me that the iPhone 3.1 beta 2 phones home to the mothership in Cupertino to verify that your iPhone's unique identifier (a.k.a. its UDID) is on file with Apple. I'm not sure if this was just added in beta 2 or if its been there since beta 1, but either way you may want to sit this one out -- or cough up the $99 to become a legitimate iPhone developer.