In case you missed it, the iPhone 3.0 software will be available worldwide on June 17th (today for developers). It will be free for iPhone owners and $9.95 for Touch. There are also some new features unveiled at WWDC.
There is also a new "Find My iPhone" feature that is available to MobileMe customers. It shows users where their lost iPhone is on a map. You can even send it a remote wipe command to protect your sensitive data in the event that it is stolen.