Those cool sidebar floaters that keep your HOT HOT links right in front of the viewer's eye...they are great to help direct traffic to certain pages and places.
Here's a great WordPress plugin that gives you that ability. Lot of options; add any link to a button, left or right scrolling, similar to Mashable.com, can display all social sharing buttons...and more...
http://wordpress.org/extend/plugins/digg-digg/