A .zip of the Weather Icons used in the test_ivweather.php demonstration script can be downloaded here: http://www.gizmola.com/blog/index.php?serendipity[subpage]=downloads&thiscat=3&file=5
There are large and small icons, each named with a number corresponding to the Interceptvector WID returned with current and forecast weather.
A list of the Icons by WID is Here.