I have a lot of devices that I’d like to keep the same calendar in sync on: Two phones, an iPaq, my work PC, my home PC and Google Calendar. The smartphone and iPaq played nicely with outlook but there was some “glue” needed to get my Sony Ericsson phone and Google Calendar in on it.
The “glue” is a few pieces of software I found recently. First of all, to sync my Sony Ericsson with GCal I use GCalSync over GPRS, then to sync GCal with Outlook I can use either Companionlink for Google Calendar (a little buggy, doesn’t auto-update, not free) or RemoteCalendars which is Open Source and very flexible. A no brainer which one I picked, really.
More info on using RemoteCalendars with Google Calendars on jakeludington.com