Dunno if that has been posted here, I haven't seen any post on this topic. If you stay logged in Diablo as well as WoW you can't be logged off in the former one. Dunno what exactly you can do with it, I'm camping rare mob spawns ATM.
Found it after I've left WoW for a couple of hours open in the taskbar. When I switched to it back I've had a bunch (nearly 20) of warning messages in the chat, saying I've been AFK too long and I'll be logged out soon. But there was also a red warning message in the upper portion of the screen saying I can't be logged off right now.
If that's a repost - my bad. My first post, I've been a lurker here for a couple of years
EDIT: a more detailed guide what to do with that idea & how to set it up more efficiently.
Rare Mob hunting for fun & profit
1.Install NPCscan, if you don't have it up already. NPCscan overlay also helps.
1.Go into Options --> Sound and check 'Sounds in Background'. Turn of the music & ambient volume, turn sound & master volume up.
2.Go into Options --> Graphic and switch display to Windowed.
3.Now whatever you do on your PC you'll hear a warning horn when a rare spawn is found.
What to hunt for?
1.Aeonaxx for Reins of the Phosphorescent Stone Drake
2.Time-Lost Proto-Drake for Reins of the Time-Lost Proto-Drake
3.Poseidus! for Reins of Poseidus - possible gold mine!
4.Mysterious Camel Figurine is also an option (Reins of the Grey Riding Camel)
For the 1,2 & 4 as those mounts will become account wide - camp them on a low population realm. Poseidus is another matter, as you want to get it on a realm where you can sell it high (unless you want to use it yourself).
5.Hunter pets - spirit beasts included
6.Hunt rare spawns for Frostbitten and Bloody Rare achievements.
7.Mists of Pandaria rare spawns! Things you might be looking forward are
-Forager's Gloves - cuts down the time of picking up herbs/ores by 1.5 sec
-Elixir of Ancient Knowledge - boosts exp gain by 300% for 1 hour
-Hozen Peace Pipe - grants 1000 rep points with all MoP factions
-Overgrown Lilypad - gain Druid's Symbiosis skill, without the need for said Druid
If anyone has any suggestions about what else is worth camping - please leave it in the comment, I'll try to update this post every now & then.