Sync your BlackBerry's mail, contact, and calendar apps with your Google Apps account using your mobile carrier's BlackBerry Internet Service (BIS). Follow our instructions, but for more support, please contact RIM.
Use Google Talk for BlackBerry® (supported by BlackBerry)
BlackBerry provides a Google Talk client that you can download to your device here:
Then chat with your Google Talk contacts directly from your BlackBerry. Learn more
Mobile apps overview
Here's a look at just a few of the apps you can use on your BlackBerry: