I've been a fan of SimplySarc for some time now and he is one of the reasons i realized that the possibilities within minecraft start to get somewhat endless.
This creation of him is featuring speech bubbles for you, your mobs and villagers based on water bubbles which gives a damn cute effect as well. This can be used in your adventure maps and world creations or even on servers for a funny way to have "over user emoticons".
What am i talking, just look at the video and make sure to subscribe SimplySarc (this is no ad, i just really appreciate his work)