I remember the old day when I used to create icons for old windows version operating system, I used to hurt the images much to reach the required color limit for the operating system. Now, I can use high quality images is icons, not only for application but also for websites as well.

3 Icons

3 icons PNG & ICO
256×256

Designers Icons

Designers icons. PSD layerd, free for personal use.

Snow E2 Aqua Icons

Icons contained in set (48 icons)

Office Tools Icons

Icons contained in set (8 icons)

Carries pencil icon,Hole punch icon,Paperclip icon ,Scissors icon ,Mail icon ,Cutter icon,Pen icon ,Stapler icon

BLACKVIS,GreenShit Icons

Pre Desktop Icons

Icons contained in set (3 icons)

Pre Web icon  ,  Pre Mail icon , Pre Contacts icon

Modern Hardware Icons RELOADED

37 icons in PNG format which go well with lightish/white wallpapers.

Lollipop

Bright! – a free icon set

Bright! is a crisp, sharp and beautiful set of 148 hand-crafted icons in vector format, ideally for both web and print work. You can use Bright! for personal and commercial projects at free of charge.

24 More Cute Icons

iPhone icons

Some iPhone icons. Includes blanks of some of them, like the weather, timer, SMS etc.