Whoimi
Whoimi adds your name in front of your chat messages. Can be enabled for guild (and officer), party and raid chat messages.
E.g.:
[Guild] [Yourchar]: Some chat message
becomes
[Guild] [Yourchar]: (Yourname): Some chat message
Usage
You can use the GUI config dialog or the slash commands /Whoimi or /inc
Slash options
config - Open configuration dialog
enable - Enable or disable adding your name to chat messages
name - The name that should be displayed in your chat messages
GUI options
Enable - Enable adding your name to chat messages.
Name - The name that should be displayed in your chat messages
Guild - Add name to guild chat messages
Party - Add name to party chat messages
Raid - Add name to raid chat messages
Channel - Add name to chat messages in a custom channel
Debug - Enable debugging messages output. You probably don't want to enable this