The Image Widget Wordpress Plugin - Rating, Reviews, Demo & Download
Plugin Description
Using this simple image widget you can display a clickable image in any sidebar.
You can set the image to link to a URL of your choice or make it pop-up in a lightbox.
The widget uses WordPress’ built in media manager to provide you with a familiar interface for image upload/selection.
You can select the widget’s image size from the available drop-down menu which lists all available WordPress default image sizes.