Using a geographical sun in Blender 2.5

In architectural visualization projects we often have to use a light that simulates the position of the sun, at a certain date or season. This is used to study the sunlight over a facade of a building during the year. In Blender 2.5 I still didn`t had any option to use a geographical sun to play with. For those of you waiting for an add-on about geographical sun, we now have one available, and you can download it from this thread at the Blenderartists forums. The add-on will appear at the Lamp panel just like the image below shows, letting us setup the sun using a lot of parameters.

For instance, along with a latitude and longitude, we can pick a day, month and even a certain hour to position our sun.