Repeating this here for anyone who doesn't read the maps thread.
I've just wiped the world, and this warrants repeating in the Good Neighbor Guidelines thread:
Originally Posted by Brad
I would ask everyone, though, to please don't go hiking away for thousands or tens of thousands of blocks in the name of exploration. In just the last week, the world has grown to 894 MB, and that kind of growth is absolutely unsustainable. To compare, the preserved regions of CC account for a "mere" 46 MB, and that's a surface area of 2.3 million blocks. The entirety of the CC world before trimming to the town was still just 434 MB. I don't want to use a plugin to force a cap on the navigable distance from the origin, but I'm looking into it because I may have to.
tl;dr: Don't go wildly expanding the world.