Hi Joe,
I mentioned it in another one of your threads, but the calendar has a nifty RSS feed that can be used to notify people who subscribe to it when new events are added to the calendar.
If you’re looking for other notification methods, thereĀ are definitely a good number of plugins available that add stronger notification features to WordPress. The best one really depends on what your needs and, while I don’t have a solid recommendation off the top of my head, this search of plugins should help as a starting point for you to check out some good leads.
Cheers!
Geoff