Player Link Menu 

This addon was written by Viper (http://www.viper.dk/WoW/) and published on WoWUI by the user Ryiort. I'm only keeping it alive.

This add-on allows you to open up a menu when clicking on a players name in chat. This will give you some basic options, for fast and easy access. So no more having to write when wanting to invite a player you're talking to or if you want to ignore that player.

It also extends the options available when clicking on a name. You can choose what actions should be performed when doing a normal click or while holding down Shift, Ctrl or Alt. It is all configurable from inside the game. Type /plm to view the options screen.

This add-on was developed before Blizzard added the same functionality to the defaul UI. However using PLM gives you a few more options to customize the menu and click behaviours to your liking.