I’ve created a public Google Calendar with important upcoming events related with Open Source Geospatial world. The information is gathered from http://www.osgeo.org/events. I’ll keep the calendar updated, so, you can subscribe by using the links on the right column, at section “Upcoming events”.
UPDATE 2010-06-29: The events have been added to the geomatic calendar created by Jorge Sanz. Now, we work together in the same calendar. So, the subscription links are from this calendar.