If you are looking for some icons to use on your web or desktop application then this icon set will definitely save your time in the GUI process. Check out Silk Icons created by FAMFAMFAM.

“Silk” is a smooth, free icon set, containing over 700 16-by-16 pixel icons in strokably-soft PNG format. Containing a large variety of icons, you're sure to find something that tickles your fancy. And all for a low low price of $0.00. You can't say fairer than that.

Download the Silk Icons here.