If we want to get control over finally rendered output of ASP.NET controls like Menu, TreeView, DataList etc, we can use CSS Control Adapter. This adapter emits CSS friendly html output and can significantly help when using CSS on the website. To know more about this adapter, follow this link - http://www.codeplex.com/cssfriendly. To see the difference between the html generated with and without using this adapter, follow this link - http://www.asp.net/CSSAdapters/Menu.aspx
Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.