No matter how cleverly or reliably you set up a system for sharing calendars, it all depends on your partner / spouse / work colleague / children / significant other looking at the calendar from time to time. What if they don’t?
George Starcher has the same problem as I do, and he has the answer. He explains how to create an Automator action 
that will pull out the events for the upcoming week from individual iCal calendars and email them to your significant other and/or negligent fellow worker.
Moving carefully through his steps in Automator and setting the resulting plug-in to run in iCal takes about five minutes.
Some of this steps are, in fact, unnecessary. You don’t need to create a calendar for the plug-in in iCal first, saving it as an iCal plug-in will create an Automator calendar for you.
The end result is a nice email full of what’s coming up:
Of course, success depends on the theory that the significant other is more likely to read an email than look at a calendar. YMMV.
A plugin for iPhoto exists that 
Scalp is a bundle for iCal that enables the sharing of calendars over FTP, SSH or SFTP connections.
CalTalk is a helpful app that enables the sharing of iCal calendars over a local network using the Bonjour protocol built into Mac OS X 10.
Publishing iCal calendars is most easily done via .Mac or on server using WebDAV.
I guess that everyone on the planet now knows that Google 
