Affiliate Link Ad Plugin

Hi,

I am looking for a widebar widget that I can place affiliate ad links into. Something with a box frame setup like on these sites would be excellent:

–http://www.wprecipes.com/
–http://digwp.com/
–http://www.smartpassiveincome.com/

Is there a WPMU plugin for that? Scrolling through but havent seen one.

Thanks