It seems like a gross oversight, on Apple's part, that there's no external indicator for notifications on the iPhone. This means that unless you happen to see a push notification come through, you have to unlock your handset to see if you have any missed calls or text messages.
Apple tried to remedy this issue with a new feature in iOS 5 called LED Flash for Alerts. It uses the iPhone's camera flash to alert users that they have new notifications, but for a number of reasons, this solution is far from perfect. Enter the new FLASHr case by Phaze5...