I've mentioned meeting wizard before as a way of getting a common meeting time for a group. I've used it off and on with varying success. I just ran across another one, MeetOMatic.com. MeetOMatic is considerably simpler than Meeting Wazard. The problem with both is that they require people to (1) click on a link and (2) check all the dates in the page against their calendar manually, and (3) check boxes on the page with the results. Seems simple, but my experience is that many don't respond. What we need is CalDAV and true, cross platform free-busy.