MFG Labs Iconset
Here is a very interesting concept, icons presented as webfont. MFG Labs has done just that. They created a webfont that contains not text, but icons. The icons are made with vectors, which means they are scalable. Private Area Use Unicode is also used to avoid conflict with existing characters. Last, but not least, you can customize the icons using CSS. Check out their github page for more details, including sample codes.