Spanning Sync is a great new program currently in beta which allows you to sync your iCal calendar on your Mac with a Google Calendar. I use iCal on my Mac basically as my diary, to help me keep track of where I need to be, and it’s really handy as it syncs on my iPod.
However, the draw back is that you can only edit the calendar when you’ve got your Mac with you. Even though I’ve signed up to the .Mac service (which isn’t cheap) you still can’t edit your calendar online. So although you have to do it via Google Calendar (so you need a free Google account), Spanning Sync at least allows you to edit your calendar online (i.e. when you’re at work and you get a new appointment) and when you get home, it’ll be there on your Mac’s calendar.
It’s free for the moment, but there’ll be a charge once it’s out of beta. If only .mac had that service, it might be worth the £69 annual fee!