Apple has released the Find My iPhone app on the iTunes App Store. If you lose your iPhone, iPod touch, or iPad, simply install the free app on any other iPhone, iPod touch, or iPad, and you can display the location of your missing device. You can also remotely trigger the missing device to play an alert or erase its memory.
In order to use Find My iPhone, you have to be a member of Apple's Mobile Me service, which will set you back about $100/year. And if you're thinking of waiting until you lose your device and then signing up for Mobile Me afterward, don't; you won't be able to use Mobile Me to find your device unless you sign up for it in advance.
In our opinion, paid add-on services should provide additional features. For example, charging for Mobile Me's e-mail and web hosting seems reasonable enough (unless you signed up for it when it first came out, when it was free and Apple claimed you could keep it forever). The paid model should not be used for protection against loss, theft, or crime. After all, Apple itself recently learned how easy it is for a phone to become lost or stolen, and if a phone has the capacity to guard its owner against injustice, the owner should not have to pay extra for it. After Apple displayed such a self-righteous attitude when their own prototype model was lost, claiming they were taking such harsh actions based on principles and doing the right thing, profiting off of crime should be the last thing Apple should be doing.
But that's exactly what they are doing. There is no way for anyone to offer a competing service to Mobile Me that offers its own Find My iPhone feature that works the same way, so Apple is essentially telling its iPhone customers (who already pay some pretty high service charges) that they need to pay for Apple's additional service or be at the mercy of thieves who might steal their device. This simply makes no sense.