I like Google Calendar because it is available from anywhere as long as you have Internet access (including on an iPhone ...) and there is no synchronization problem if you use it with several devices: all of them are using the same datastore. One thing I was missing though is that I didn't have my work meetings in it. And doing things the other way around would have been neat: having my personal stuff displayed in my Outlook calendar is usefull when you are planing meetings late in the evening or business trips.
My goal was not to synchronize the calendars (I wouldn't risk to mess-up my Outlook calendar with the synchronization process) but rather to have each calendar displayed within the other one in read-only mode.
Here is how I did it:
1. Setup the Outlook -> Google Calendar export process and schedule it every 15 minutes
The most simple, automated and reliable way of displaying my work calendar in Google Calendar that I found is to export it using SyncMyCal. This is not free ($25), but not too expensive either and it works very well. Also it will work fine behind a company proxy server which requires authentication.
To set this up, install SyncMyCal and go to Settings / Sync operations. Click "add" to create a new operation and apply similar settings to the ones in the following screenshot. Beforehand, create a new calendar in Google Calendar which will host your Outlook Calender - in this example it is called Outlook *hidden* (the hidden part in my company's name).
Then, if you need to setup a proxy server you can do so in Settings/Advanced Settings/Connection.
At this stage you can run a manual sync and it should populate you new Google Calendar with your Outlook appointments.
The last thing is to go to Settings/Advanced Settings/Auto Sync, make sure Auto Sync is enabled and set how often you want it to run (in my case every 15 minutes).
That's it, now as long as your work computer is on it will feed Google Calendar with any change in your Calendar every 15 minutes.
The result in Google Calendar looks like this (the blue events were created in Google Calendar, and the green ones came from Outlook):
2. Setup Outlook (2007) to display Google Calendar appointments
This second step is much simpler as Outlook 2007 can display remote iCal calendars, which is supported by Google Calendar.
To set this up, first go to you Google Calendar settings, on the calendars tab, and click on the name of your main calendar. Under the private address section, click in iCal and copy the URL of the calendar:Then in Outlook 2007, go to Tools/Account Settings, and open the Internet Calendars tab.
Click on New, and enter your Calendar's URL.
If you go to the Calendar view, your Google Calendar should now appear under My Calendars.
To see the meetings from both calendars on one view, thick both of them under My Calendars. If they are displayed side by side, go to the View menu and select View in Overlay Mode.
The result in Outlook 2007: