Those apps that changed your Pearl’s trackball colour always seemed a bit useless to me, but fresh from the guys who made that the BlackBerry-finding software, is PearlCast. Basically, you can assign different trackball colours to different temperature ranges, so when PearlCast receives the latest weather forecast for a particular zip code, it will change the trackball colour. Pretty nifty, but it would be nice if you could change the temperature values, since the weather won’t change within 20 degrees too often. You can also set changes based on current conditions and one-day forecast. Thanks Stefano!