Here is another icon set that I made nearly two years ago. I always planned to make over 1,000 of these but never got round to it. There are 310 of them and they are designed to be used on web design projects, but some are also suited to be used as system icons. They are all 16 by 16 pixels, in PNG format and free to use in print and web projects.
Slowly chipping away at getting this site fully online, I've made a number of 48 by 48 icons for use on the front and back-end of the site. I'm releasing them for free use under the Creative Commons (by) licence.