For all my friends with Gmail accounts, Google launched Google Calendar sometime last night.  I figured those who already have Gmail accounts would find this most useful because they don't have to set up a new account, as all you need to do is log into and use your Gmail username and password.  30 Boxes still has more functionality, but it is mainly stuff that most people will probably not use.  I'm sure Google will roll out more features in the months to come.  You can set up events, public and private, and invite people to those events.  And it is easy to do.  I may talk more about Google Calendar later when I've had more time to play with it, but right now I've got things to do.