Apple on Monday released iCal 1.5.4, an update that offers better security when importing events with alarms as well as other performance improvements. You can run Software Update to get the new version or visit the
iCal download page
to get the full application. You’ll need iSync 1.2.1 or higher to synchronize your iCal data with another Mac or a cell phone or PDA, as well as a .Mac membership or access to a WebDAV server to publish your calendar online. Mac OS X v10.2.3 is required.