Finally, Google releases a way to sync your Google calendar with your Blackberry. Awesome. Get started here.
Update (12/13/07): It’s not quite as easy as they make it sound. I assumed it would be included in the “Download All” package they offer, but it turns out it’s not. You actually need to scroll down the page on the link (http://mobile.google.com) they send to your mobile phone and choose “Google Sync”.