|The Most Interesting Mapper in the World|
In case you live under a rock, this particular meme has its origins in a set of beer commercials that I find kind of amusing. Here is a decent compilation of them.
<sorry to interrupt this completely awesome post but quick note: This plugin has been turned into a core JOSM feature. See "Update 2" at the bottom of this post>
But seriously, the ImproveWayAccuracy plugin is a wonderful tool. Perhaps the prime use case to show it off is a smoothly curving road that was originally either mapped from low resolution imagery or (around here) imported from TIGER data that may have used far too few nodes to make a smooth curve. To fix this by hand is highly annoying. You have to drag nodes around and then grab the + between two existing nodes to create a new one and drag it to where you want it, repeating that as often as needed to achieve a smooth enough curve. Each node requires several precise mouse movements.
It is much easier to draw a way from scratch where you just move your mouse along the curve and click as needed to form a smooth looking curve. Well, the ImproveWayAccuracy plugin makes this possible to do with existing nodes/ways!