Well I am logged into calendar.google.com pretty basic but free. You will be able to create multiple calendars of which you can make them private or share it. The one thing is obvious Google wants you to stay logged in. If you do then when appointments are near it will put up a pop up on your screen. Nice start. [calendar.google.com]

RSS feeds available I found the RSS feed, you have to dig around to find it, go to the left hand side click the down arrow by your name, and you will see calendar settings click that and you will be presented with a private feed URL if your application supports ical you can link in with that as well.