Free Social Media Icons Pack under Creative Commons
Social Media Icons Pack includes 3 sizes for 17 icons: 128×128, 64×64 and 32×32. There is an icon for the following: Blogger, Delicious, DesignFloat, Digg, Facebook, Flickr, Google, a heart icon that will work for anything (such as bookmark), MySpace, Reddit, an RSS icon, StumbleUpon, Technorati, Twitter, WordPress, Yahoo! and YouTube.
These icons are released under Creative Commons Attribution 3.0 License. You are free to use them on both personal and commercial projects.
License: Creative Commons License