Eddie Awad's blog posts have a nice row of social bookmarking icons at the bottom. These are courtesy of the Sociable plugin for WordPress. Each of these bookmarks the post at the associated social bookmarking site.
I have always thought it would be nice to have this on my blog. Since I can't use plugins willy nilly at WordPress.com, I had to find another way. Enter the Socializer by Pierre Far. Provides a way to bookmark your blog on a whole bunch (~40 at last count) of bookmarking sites. To make it easy to use:
Not the same thing, but a pretty good hack even if I say so myself.