1,401 icons in 26 icon sets
Free Large Business Icons represent a free icon collection well-suited for websites and programs associated with all sorts of business activities. The pack delivers images depicting various business-related subjects, such as Safe, Printer, Card File, Hard drive, Cash register, Trailer, Zoom, Phone, House and more. Large Business Icons are free for personal and commercial use (under the Creative Commons Attribution-Share Alike 3.0 license).
More quality vector and raster icons are here: http://www.aha-soft.com/iconsets.htm