Bookmark Now plugin for WordPress adds a list of XHTML compliant graphic links at the end of your posts and/or pages that allow your visitors to easily submit them on social bookmarking / network sites. Furthermore, the plugin adds a page in the WordPress admin section that lets you customize it.
Bookmark Now support the following social bookmarking networks:
BlogRO, Del.icio.us, digg, FURL, Socializer, reddit, Feed Me Links!, Technorati, Newsvine, Ma.gnolia, Google Bookmarks, Squidoo, Stumble Upon, Blogmarks, Scuttle, Bloglines, Ask, Live - MSN, Slashdot, FaceBook, Blogsvine, Mixx, Scoopeo, Myspace, Twitter, FriendFeed and many others.
You can download it from here: