Recently we made a post about fun small icons. Small icons though are not only funny icons. Here is where Iconfinder comes. Iconfinder is a search engine that searches only for icons, that are free for download and licensed under GPL or BSD licenses (most of them). Search results are developer oriented (searching for “pirate” icons will get you no results, but searching for “database” icons will get you many).
Iconfinder is very easy to use and results come with icon previews, links to download and information about licenses. All icons featured are in PNG format with the benefit of transparency. This service is in BETA mode but it works almost well. A search cloud is also provided to tell you whats popular. A blog is also there to inform you about whats is going on in the labs. Worths a try!