I'm hearing a lot of stuff about new features and that some apply only to iPhone 4, and not to 3GS. For one, the Find my iPhone feature, it can be used on the 3GS but only after being activated on a newest generation iOS device. I'm also hearing people saying that the new SMS tones are only for iPhone 4... is that true?? Are there any other features that are left out of the 3GS? Is there really any point in updating a 3GS??