I popular addon i found that really helps me out when i afk bot is called Elephant ( Elephant | World of Warcraft @ Curse.com ). All the addon really does is keep track of all the chat messages you receive including whispers and bg chat. In the worse case scenario of a gm whispering you or getting an important message from a friend or guildie while afk, you can always check back to it.
I also find this addon useful when im just generally afk or when i need to recall on something someone said to me awhile back.
Anyways. Just thought i would make a post. GL guys.