Install this plugin to add theBlonk sidebar. The theBlonk is a free blog promotion tool between participating blogs.
theBlonk ("the blog link") is a tool that bloggers can use to help promote their blogs across the blogosphere. A blogger places a widget on their site that displays relevant posts from other bloggers, and in return their posts are displayed on other blogger's pages as well.
You can check out http://www.theBlonk.com for more information