One of the most often requested features for ASP.NET has been to support a common look and feel for a site. The Master Pages feature within ASP.NET 2.0 pushes this capability to the forefront and makes developing a set of pages with similar aspects a very doable proposition. In addition to Master Pages, ASP.NET 2.0 Themes represent a way to apply global style attributes to all the pages in your application.
ASP.NET also supports specifying default values for specific server-side controls through a Skin file. Skins offer a finer-grained approach to applying styles in a control-centric manner.