MeetWith.Me has created a way to do just that. I can now add a widget to my website that shares my calendar for clients and others to see. Others cannot see who I am meeting with, but just my availability.
What I would like to see in future releases of this service: a widget that I can properly resize for my website columns, and a way to embed the full calendar within my own site. I do love the idea that clients can review my schedule and compare it with their own BEFORE scheduling an appointment with me. Check out my calendar