I am trying to find alternative symbology for GIS maps and web apps I occasionally produce. Esri has done a great job collecting and categorizing thousands of symbols, markers, line and polygon styles. For instance, here one can find all 9.3 symbology available in ArcGIS. They are available as individual categories here, too. I have also seen a great resource page on Esri Mapping Center with lots of additional styles. Quite many links on symbology standards here, too.
I am however looking for any good resources with symbology that can be not necessary related to mapping/physical geography, but rather something that describes world around us. The one I liked really much is available here, which is part of this library. I fully understand that there are plenty of resources like mapicons. Any other website worth visiting when looking for icons for map symbols?