A Set of 128 Free Icons (.png, 48×48px) ready for your blog, website or any other web application. The collection includes social media icons such as: Design Float, Digg, Delicious, Furl, Technorati, Flickr, Stumble Upon, Twitter & Many more…

I don’t know why they didn’t include also 16×16px icons, so we don’t need to resize and lose quality …. anyway free to download:

http://wefunction.com/2008/07/function-free-icon-set