You can find hundreds of free icons to download all around the web. Google for interface icons and freebie sets, you are bound to find hundreds of thousands of results! It can be a pain going through all these potential links and finding the best quality interface icons.
That is why I have put together this showcase of 23 personal favorite icon sets. These are all free to download and work perfect for web & mobile interfaces. Any new project can be greatly enhanced by a nice suite of icons. Along with the list above, feel free to share other examples of freebie icon sets in the post discussion area.