[For Designers]: Very cool icon font
Check out the download and slider button at the top. You can download the font, and check out the spinning icons. Since it is a font, the icons are scalable. Very cool animated ones, see screenshots below.
To install this font, download the font (extension is .ttf). Open up finder, while clicking on Option key > click the Go (menu dropdown), which will display "Library" -- for Mountain Lion (otherwise you might have to access your Library folder using Terminal). Drop the font into your font folder.
Where was this site a couple of years ago, when I had to create my own icons in Adobe Illustrator, and worry about the scale and concept of each icon? (Sigh), now you have it :)
I believe you can take this font, and modify them using some open source software (exports true type - .vfb or .vfbak), but I have not researched this yet.