New Idea Monday #9 imap protocol for calendars and contacts

So I have been using Evolution on my home computer, laptops and work computer for a while.  All the email servers that I use support imap as a mail protocol. This got me thinking that there should be a imap protocol for calendars and contacts.  I could create entries and these would follow me arround no matter what client I used. iCalander is great for sharing the data but I just want a common place to store it. Seems like a imap like protocol would fit the bill. Perhaps an imap that groks ical?