Iconfinder.com - Search Engine for Icons

            Iconfinder.com provides high quality icons for web designers and developers in an easy and efficient way. This is the best place to search, sort, filter, and find icons for any occasion. At the time of this writing the site currently has 318,060 icons in its database!

More than 100000 free icons in one place and you can download all the free icons in PNG or ICO format.

It have a nice filtering option that lets you choose to show only icons that can be used commercially, commercial that doesn’t require a back link or all icons. You can also change the background color of the icons to white, black, or grey. This will let you see what they look like on your site or application.

You can additionally filter the icons by size anywhere from 0 to 512px. This helps you find the proper size without having to re-size and possibly pixelate an icon. If you want to see more icons per page, it gives you the option to see 18, 24 or 48 icons per page.

If you are a firefox user there is an add-on available for iconfiner.com, Install it from here.