Ok this is not the most efficient system in the world. But this should be something you could make in the first hour or two of game play. You can get loads of cobble and usually enough iron for two buckets. If your not into collecting a bunch of cobble by mining you can usually fine at least one block of lava within the first hour if you dig down and could use that to make cobble gen. Obviously this is much easier in modded MC but since everyone keeps asking me how I can get stacks of ender pearls without going to the end I figured I'd share this. So first how does this work? Well we are going to use endermen argo system to our advantage. Since you can look at them form 128 blocks away and still have come after you that is the effective max range of this build. For this I made it small just so you can get the idea of how it works. You can make this much bigger if you want. To make this at least some what efficient we do want to max out spawning so take note of ground level (oceans are best for this to be honest) you want to go at least 128 up to remove stuff spawning and taking up mob slots. Ender Trap by Saice, on Flickr Ender Trap by Saice, on Flickr Make sure to ladder this up as you will be using this often to reset the system. Ender Trap by Saice, on Flickr Next build a sort of base. Add the water on top for two reasons. We want nothing to spawn here and we want to minimize where endermen can TP to. This also makes you an infinite spring so you will have all the water you need for the rest of the build. Ender Trap by Saice, on Flickr Build your kill area. The fences are there just in case and like the base area you want water on top. Note in 1.6 zombies have a HUGE scan range now so the fences are more important in 1.6 also if you have a mod that has ender tots the fences are needed. Ender Trap by Saice, on Flickr Ender Trap by Saice, on Flickr Now to use some basic spawn know how. So we need to take note of our location behind the fences. Nothing is going to spawn 24 blocks form this point so we want to go 24 blocks out and build a spawn pad. Ender Trap by Saice, on Flickr Ender Trap by Saice, on Flickr You don't have to have walls and or course you can make this as big as you want as long as no point is more then 128 from your kill box. Ender Trap by Saice, on Flickr As with the rest add water. I like the gap as it makes it easier to spot endermen but you can close it up. With this setup it is only going to work at night. One option if you want the gap for spotting is to make the roof go an extra 14 blocks out on all sides this will make it so SL is 0 inside the box. But I just wanted to get this done with the basics. Ender Trap by Saice, on Flickr Ok I know a bunch of folks are going to go Why a bridge endermen can teleport? Well not really or at least not how you think they do. Most of the time they are using normal mob pathing and just zipping along really fast. They can Teleport but there AI does not jump straight to that and unless you want to make this take a lot longer then needed I suggest this bridge as they will run and zip across it. Ender Trap by Saice, on Flickr Now you just wait. When Endermen spawn look at them and they will run to you. Kill them and get your pearls. Ender Trap by Saice, on Flickr Ender Trap by Saice, on Flickr Ender Trap by Saice, on Flickr Now this is not super fast but is also a great time if your using soulshards to get yourself an enderman shard. When to many other mobs spawn or in 1.6 you get a mass of zombies run down your ladder its more the 128 blocks from the bottom of that to the spawn pad so a few moments and everything despawned run back up and the pad is reset. Repeat as needed.