A free Windows Live Messenger version for Java cell phones has been released. It supports cell phones manufactured by Motorola, LG, Samsung, Nokia, RIM and Sony Ericsson.
For using Windows Live Messenger for Java phones, you need a Windows Live ID, just like with the PC version. With this recently released Java client, you can chat with multiple contacts simultaneously. According to Microsoft, that’s also possible at the same time.
Furthermore, all incoming messages are sent directly to the user’s cell phone. You can manage your contacts as well as information about their profiles or their status.
You can send yourself a SMS containing the download URL for the Java client via the corresponding website. If your device is not supported, your cell phone will get redirected to the browser version of Windows Live Messenger automatically.
More information: Windows Live for Mobile