I recently came across this HUGE collection of freebie icons (512x512, transparent PNGs or ICOs) from Samantha Wright at DeviantArt:
I can’t say enough good about them. They became an integral part of the look and feel of the design I’m currently working on. If you’re designing with any sort of faux-Victorian, steampunk, or even some flavors of decadent grunge themes or feels, you should check them out. She designed them for use in desktop apps, and some of them aren’t useful for anything else, but hell, there’s over 900 of them (big download), so you’ve got lots to choose from.
I don’t know Samantha Wright, and I’m not shilling for her, but her work is so extraordinary for free icons/graphics and so useful for Web designing that I wanted to give her some kudos.