A cool application for BlackBerry is BluCTRL which is a BlackBerry app that turns your BlackBerry smartphones into a Bluetooth mouse for your PC.
BlueCTRL is easy to set up; there are two files, one for the PC and one for your BlackBerry. All you do is install both files and pair up and you are ready to rock using your BlackBerry as a Bluetooth mouse on your laptop or PC.
BlueCTRL for BlackBerry is donationware, so you can download it, try it out and just give back to the developers if you are happy.
Source — crackberry