There's an application for that called Viper SmartStart. The application will lock and unlock doors, pop the boot, sound the alarm and start the vehicle all from a simple interface. The application will be free in BlackBerry App World, but the hardware for your car will set you back anywhere from around $300 to over $600, and after the first year the service will run you another $30/year.
[Source: Crackberry.com]