RIM is really piling it on with their patent applications and approvals. This one was applied for in January of 2011 so it is not recent but it does cover detecting emotion in your words. The idea is that your phone will detect the emotional context of your message and present that determined emotion in the message. Your emotions are captured from multiple sensors on the device (mood ring BlackBerry anyone?) and sent in a standard format.
Here is how RIM describes it:
DEVICE AND METHOD OF CONVEYING EMOTION IN A MESSAGING APPLICATION
The present disclosure provides a device and method to convey emotions in a messaging application of a mobile electronic device. An emotional context of text entered into the messaging application is determined and an implied emotional text is presented for at least a portion of the entered text in accordance with the determined emotional context. The emotional context may be determined from captured sensor data captured by one or more sensors.