I'm studying permaculture design. Its goal is to set up virtuous, sustainable ecological cycles that work to the benefit of everyone. One of the basic pieces of information that's needed is direction of the sun during the course of the year.
I'd looked at this before and eventually figured it out, but Vladimir Agafonkin has given the world a wonderful site called SunCalc that overlays sunlight information on a Google map.
For an example, here's a nearby park at noon this past vernal equinox.
With the use of that plus this shadow length calculator, I was able to figure out a lot about sunlight and shade on my property.