I’m typing this in between perusing Facebook, trying to master a guitar-simulation game and listening to Internet radio on my smartphone. And no, I’m not using an iPhone. I’m using a BlackBerry Curve 8900 to try out the recently rolled out BlackBerry App World. Lately, any smartphone maker worth its salt is operating or about to launch an application store that corrals all kinds of free and paid software you can download straight to your handset. Apple started the trend with July’s release of its App Store for the iPhone and iPod touch.