WATERLOO, Canada - One of the better innovations from RIM on the BlackBerry series of smartphones is the new trackpad. The Curve and the Bold both have the new device, on the new models. The new trackpad replaced the rolling ball, which was a good pointing device until it clogged from use. The trackpad now provides a reliable pointing device for the smartphones with hard keyboards and no touchscreen.

Inside BlackBerry has a detailed tutorial on the science behind the trackpad. The pointing device is a LED illuminator and a low-resolution fast frame-rate camera that senses the imperfections on one's thumb to determine direction and velocity. An algorithm calculates position and position changes, moving the cursor around the screen.

Obvious advantage over the rolling ball: no moving parts to collect dirt and grime. Like any camera-based system, the lens will get dirty and degrade performance. A quick wipe with a clean soft cloth is all it takes to get optimal performance.

This is a great improvement over the ball, removing one of the weak points in the BlackBerry design.

More on RIM smartphones at the BlackBerry Lovers Blog.