Google is making its Google Talk IM service available on BlackBerries.

Google Talk for BlackBerry has been designed specifically for BlackBerry devices. It will be much like Google Talk for PCs so when users download the client software they willl see existing Google Talk contacts, be able to add and alter contacts, know when contacts are online and send and receive messages. Users will be notified on the home screen of the BlackBerry when new messages arrive in Google Talk.

BlackBerry users can download the app for free but may be charged by their operator for data transmitted when using the service. It will be available in a few months.

Third-party companies have already developed similar clients for mobile devices. MessageVine launched a Google Talk instant messaging client for mobile devices, including the BlackBerry, in September.

Google also said that Google Local for Mobile is now available on the BlackBerry. Google Local users can view maps and satellite images and get directions.