The progressbar widget generates simple CSS progressbars.
This is just the widget-ized version of Tobias Lukte super-simple-css-bars: http://blog.leetsoft.com/2006/8/22/super-simple-css-bars

If you want the default style remember to call the progressbar helper with :generate_css => true at least one time per page. This will inline the default CSS. You can always grab the inline CSS and save it in your public/stylesheet folder.