Last patch Blizzard made a stupid mistake;
Scarab Coffer Key (AQ20 Trash drop)
http://www.thottbot.com/?i=52589
& Greater Scarab Coffer Key (AQ40 trash drop)
http://www.thottbot.com/?i=52848
These 2 keys can now be carried out of the instance, meaning, thats right, you can jack keys, and loot the Coffers later. When you are not in the raid group, they can't see you loot the bags/idols. Depending on the instance, each one will drop 2-3 Bags with about 5 scarabs each. Scarabs sell median for 10-15g each, and Idols that can sell as high as 120 gold.
Keys are white, and can be looted even over masterlooter and group loot.
I should note that AQ40 coffers can drop very good idols, so you may want to drop group while the monsters loot screen is up, take the key, logoff, and come back an hour later to collect your prize.
heres the same exact thing rephrased...
REQUIREMENTS:
You must obtain one of these keys from either AQ20 or AQ40, and you must have access to the instance.
Scarab Coffer Key (AQ20)
http://www.thottbot.com/?i=52589
Greater Scarab Coffer Key (AQ40)
http://www.thottbot.com/?i=52848
If you manage to obtain one, you can keep it in your inventory. When you aren't in a raid, no one can see what you looted. No matter what instance you'll get a good size amount of scarabs. Prices depending on your server. The keys are white so you can loot them no matter what loot is on.
Basically what you do, get a key, leave the raid, come back later, and loot the chest.
I wouldn't reccomend this since it's kind of ripping off your guild.