I have been using a calendar program for my Blackberry that was initially developed by a great guy in Germany, Ulrich Greve. You can get to his website by inputting PC-Software-Developments. The software was originally developed for pda's, both windows mobile and palm, but he is now using it for smart phones as well. I was using it on my old Dell Axim PDA, but he seems to have been able to transpose it to Blackberries as well, as I downloaded it OTA and have been using it successfully on my Pearl for over a year. It doesn't look quite as sleek on my Dell, but it is very utilitarian, and has just about everything you'll need in the form of a Jewish Calendar. Good luck!