Well, the newest cell phone case is called the Spraytech. Unlike the SmartGuard case, which acts as a holder for a specially made pepper spray canister, this one actually dispenses pepper spray. The pepper spray is incorporated into the back side of the case and is less bulky than other pepper spray cases. The nice thing about the Spraytech is that it looks just like any other iPhone case.
It comes with one pepper spray cartridge, but refills are available for purchase. The Spraytech also comes with a test cartridge included. Test cartridges are filled with compressed water and are great to practice with.
There are multiple safety mechanisms to prevent accidental firing. As of this writing, they are available for iPhone 4 and 4s but other models are coming soon.
Because iPhones seem to be a popular target with thieves, the Spraytech seems like a great idea. Any personal protection device is only effective if it can be deployed quickly, at a moments notice. Since many people carry their phones in their hand while walking, the Spraytech can be deployed before the criminal has a chance to react.
Click this link to purchase pepper spray or other self defense products.