I never use iron golems because they wander away into random places and become somewhat useless. what if they could be programmed to patrol a route?
So heres how it would work: you place your four iron blocks first, then you place redstone on the ground connecting to the iron blocks, you can make a route path if you have enough redstone. the iron golem follows the redstone path once its created, you can also collect the redstone once the golem is created and it will still continue patroling its route.
This seems more like a custom mod, then an actual update, but i've been thinking of a way to control and alter locations in the game that kinda goes along this line of thinking.
It used carpet and wool instead of redstone though, and was somewhat similar to the Controlblock mod produced by Bukkit .
Basically, the idea was you could use different colored wool to create areas, and colored carpet that matched the wool block would coordinate to area that you were defining.
To activate a wool block you simply left click a wool block with matching carpet, and then place the Carpet defining the area you want to manage. After you placed the carpet, you'd go back and left click the wool block again, and the placed carpet would disappear, and the game would open a GUI to allow you to define who or what could move through the defined areas.
If the area needed to be redefined, you'd get more colored carpet, and left click the wool block again, this would bring the previously placed carpet back into existence, allowing you to add to the area or reduce it. Left clicking it again would end the process and re-open the GUI.
The main use for this was to manage artificial villages better, which, would include the natural iron golem movement. Villagers have known movement bugs which can quickly make them troublesome.
The only thing that gets a little sticky is when people start talking hostile mobs, since it could be used to quickly define an area that the hostiles couldn't move through, but, in the realm of custom mods, it's not a big deal to limit it to nuetral and friendly mobs only.