Google Maps has added a new feature, Click and Drag.

Google Maps - Drag to change route

From Mashable:

Google Maps has improved its directions feature dramatically today by adding “Click and Drag”: after laying out a route, click and drag any point to have Google Maps recalculate the route with updated distance and time. It works great when you don’t like the suggested route, want to take a detour or need to avoid traffic jams and the like.

Neat feature!