EDIT: Ok, it turns out I didnt read the solution below me first. Mine is quite similar, But I feel like I went into a lot better detail and hand holding to guide you through it
I will preface this solution by first saying that I scoured all over the internet and could not find anybody EVER suggesting to do this actually very clever method. I will also say that I have not tested other classes as I only have a Witch Doctor and it may work for other classes.
1. Witch doctor with the passive skill for 3 Dogs and also the Gargantuan and a follower for a total of 5 "followers".
2. The Puzzle Ring
3. A wired controller or some way of keeping a wireless controller going for long periods of time.
4. As much gold find % as you can possibly have (maxes out at 375% just fyi)
Ok, ready for the magic? Here goes. Assuming you have followed my requirements up until this point...load up the start of the last quest in Act 3-Inferno-Easy difficulty. I'm sure that this will work on other difficulties but doing it on Inferno EASY will make sure that A) You don't die, because its easy and B) BECAUSE its on Inferno...you will be getting lvl 60 loot as well. Anyways, when you spawn in town, first go to the blacksmith and repair everything. Then go to the waypoint and go to Arreat crater level 1 and keep moving through the level until you find one of these steel dragon head fire breathing "traps" that do damage to you, Clear out all the enemies around it so that nobody bothers you. Stand yourself so that you are getting hit 5-6 times by the fire breathing steel dragon head. Voila!
Now...you may be wondering to yourself, "uhhh....Phonyspoon...what am I accomplishing? Well, young Padawan, by getting hit by the Steel Flamey Dragon Head thingamabob, everytime it hits you is a chance that it will spawn one of those weasily little Treasure Goblin/Pygmy/Whatever nincompoops. You, being a Witch Doctor with the requirements I set up for you (or being another class and figuring out ways of your own), will just sit there while your minions kill them before they can scamper off into that horrid portal.
Now that everything is set for lots of idling time, I will tell you how I test this. I set it up at about 5am right before I went to bed one night. I woke up at 1130am to a GLORIOUS GOLDEN BED of, well...gold all around me that ended up totaling about 64k. Interestingly enough he only dropped one legendary.
Herein lies the problem and the no so minor oversight by yours truly: Durability.
At some point in the night my puzzle ring and its feeble 28 durability (along with every single other piece of equipment i had on my shriveled little body), broke. Which means, you guessed it, it stopped serving its purpose of spawning those little worms.
So, here's a modification to this process: Do everything I just told you...but check up on it every once in a while. Maybe every hour or so go to your inventory and see what the durability of your puzzle ring is. If its not up to par, fast travel back to town and repair, then go back. If you are like me, try not to move at all when you are within the depths so you can pick up all that glorious loot in one fell swoop. Thanks for reading people and feel free to leave a comment and an up vote if it helped you....or at least leave a comment if you down vote please!
P.S. If you are going to leave it on for extended period of time, PLEASE for the love of god install the game to your Hard drive. Think about the poor Xboxs kids. The Xboxs.....