Sexy Bookmarks (by Shareaholic) -- if you do look below you'll the social networks panel for folks to share this article with (like Facebook, Twitter, Digg, LinkedIn, MySpace etc). This is great to encourage people to tell their close friends and family about your website or weblog posts.

W3 Total Cache (by Frederick Townes) -- Makes your blog load additional! And that in itself is awesome because Google takes that into account when ranking one's bookmark manager spot. So the faster your website loads, the better it looks in Google's eyes.