Introducing the RoundedCorner Web Control
source: http://aspnet.4guysfromrolla.com/articles/072804-1.aspx
...I decided to create a custom ASP.NET server control that would utilize the dynamic image-creation capabilities of GDI+ to create the corner images for me. The result is an ASP.NET Web control, which I call RoundedCorners, that you can drop on an ASP.NET Web page, set a few properties, and be presented with a nifty box with rounded corners, as shown on the right. In this article we'll examine how to use the RoundedCorners Web control in a page, as well as take a peek under the covers at the control's source code.