In previous article 480+ free and fresh icon sets help you to create your beautiful skins and themes in Flex we have introduced so many wonderful icons. Today we will continue. It seems the Digg, Twitter, Stumble, RSS, Delicious & Reddit become more and more popular now. It must make more attractive if use lovely icon to show them in your blog or website. Then we have collected 15 very beautiful sets of social bookmarking icons for you referece. Which important is they are all free. Why not have a try at once?