Chat Bubbles is a mod that displays things other players say above their heads in a chat bubble, like some MMORPGs
Go here http://minecraft.curseforge.com/mc-mods/235520-chat-bubbles/files to make sure you get the right version for your version of Minecraft!
Requires Liteloader. For brand new versions of Miencraft, you might need to get Liteloader development builds from the Jenkins build server. Get Liteloader betas there. With Liteloader installed, put the .litemod file into your ,minecraft/mods/1.7.10 or .minecraft/mods/1.8 folder
Works on most multiplayer servers, but if a server has a super customized format for chat lines that is far enough away from normal it may not work on that server. It is possible to make custom regex lines to add support for individual servers that are not supported out of the box.