slimScroll is a small jQuery plugin that transforms any div into a scrollable area with a nice scrollbar - similar to the one Facebook and Google started using in their products recently. slimScroll doesn't occupy any visual space as it only appears on a user initiated mouse-over. User can drag the scrollbar or use mouse-wheel to change the scroll value.
Demo and more: http://rocha.la/jQuery-slimScroll
Copyright (c) 2011 Piotr Rochala (http://rocha.la) Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php) and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
编辑有话说：
jQuery slimScroll插件是一个支持把内容放在一个盒子里面，固定一个高度，超出的则使用滚动。该插件挺好的。
不过不支持resize的时候重新调用插件，有一个贡献者已经修改过源码，不过作者并没有加进去。
我已经把项目的压缩也改过来了，你可以下载直接使用。
该插件不支持IE7。