We could turn this into a meme:
If you're going to play WoW and maybe want to party, put up a post:
Tag it WoW.
If you use Firefox, you can bookmark your WoW friends' WoW tag entries in a folder and just Open all in tabs. Here's mine.
Flip thru, see who's on...
When you're done playing or change Server/Char/Etc, either delete or update the post. I'll do it.