WorldEdit
A server plugin that makes mass block manipulation a breeze. That and Voxelsniper (long range block manipulation) and it would take nowhere near 3 seconds per block. Maybe 5 seconds per frame.
WOW! Thanks much! But come on, 3 seconds to place a block?! I'd also say it was a tad less then 10% on most frames. Thanks again We are so getting a few prints of this. :P
The number of pixels changed would be way less than 10% on non-scrolling frames, and the amount of time to place a block would likely be less than 3 seconds given the way these things tend to happen in lines and in quick succession.