If I could sync my Blackberry with Google Calendar over the air, bidirectionally, I’d be able to dump Outlook forever. (Though admittedly Google doesn’t have a particularly robust contacts system for Gmail yet and it would be nice to sync contacts too.)
One blogger reckons he’s done it. I haven’t had time to try the method out yet but I’m noting it here in case anyone else is interested (and so I don’t forget it myself!)
Google also has an Apps integration page that I didn’t know about… with a handy page about ways to sync your phone with Google Calendar.