I happened to come across this and was not going to post it but then figured I would in case anyone wanted to try it out. MissingLight makes your LED light blink purple when you have a missed call. It stops when you touch your screen. Right now, it works with the 8 and 9 Series Blackberries. This application is free and you can use the OTA download.
Anyone who downloads it, please let us know what you think about it.