invitiation

Hello all!
Hope those of you who managed to get to Drupalcon had a great time. I'm looking forward to hearing about your experiences at our next meeting.

I am looking for a way to send invitations to events when I add them to a calendar. I've created an "Event" content type that populates a calendar. It would be really helpful when adding an event if I could:
1. Select registered site members to send the invitation to, and
2. Enter email addresses in a field and have notification sent to these people as well.

Any ideas on how to make this happen in D7?

Thanks in advance!

Todd V