Did you ever use google maps to get direction from point A to B, only to have to give up and do some manual adjustments, because you wanted to make a pit stop at location C? Did you ever want to get google maps (or any other mapping program for that matter) to take you through a different route, because you knew for a fact that some road along your route was under construction? Well I have and usually I end up having to pick a arbitary point somewhere to force the mapping engine to take a certain street/highway that I want.
Well those crafty engineers at google have solved the problem for all of us. You can now input your source and destination and if you don’t like the route, just move your mouse along the outline and move the outline (through the magic of AJAX) and force it to go through another path. All this is done in realtime and the mapping engine does all the calculations while you’re moving the route points.