I think this is a pretty good way to share calendar.
Links:
[1] http://www.google.com/calendar/render?cid=rhd9474dp1ld83tkdpnbrptal4%40group.calendar.google.com
[2] http://www.google.com/calendar/ical/rhd9474dp1ld83tkdpnbrptal4%40group.calendar.google.com/public/basic.ics
[1]
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