Interesting hack. I don’t know how imminent iOS 4.2 is, but this might be useful.
“…the obvious (in hindsight) answer: They looked in my iPhone’s address book. I never said they could. What else did they do with my contacts? Send a copy to their server for safe-keeping? Foolish me, but I thought that was my iPhone and my contact list. I paid huge money for the iPhone, so it’s not like it could be anyone’s “business model” to use that data. But now, as far as I know, some unknown startup in California has all my data.”