I have no desire to enable Lion's Safari-only mode. I have disabled the guest account but still see the guest login item when I reboot my system.
Is there a setting somewhere I'm missing for disabling the Safari-only mode?
You can disable the Guest account at startup in System Preferences -> Security & Privacy -> Advanced (the button at the bottom of the screen. The checkbox says "Disable restarting to Safari when screen is locked". I believe that it leaves the iCloud settings unchanged.
This works without changing iCloud.
It looks like you can disable it wihtout disabling 'find my iphone' by following steps in this article. I doubt that 'find my iphone' will be much use though if the person who steals it can't login, but who knows.