Is it possible to change the text bubbles on the s3?
Go to the Messaging app and hit the settings button. You will see Bubble style and Background style.  

When you select Bubble Style you will see options at the bottom of the screen that you can scroll through (the top option is the look for your outgoing messages, the bottom option is the look for received messages).

When you select Background style there are a few options to scroll through at the bottom of the screen as well.