Mike makes a plea for publishing calendars in i-cal format or specifically in Google Calendar. I agree and suggest that owners of calendar information (governments, local authorities, boards) take some care when getting their information 'out there'.
I followed up Jon Udell on this subject and noted that Google's Calendar API makes a good effort at parsing all but the most obscure presentations of event information. If you do publish event details on the web, make it easy for your audience to capture the information into their calendar. You can be really helpful by adding a specific Google Calendar button for the event.